---
_id: '13234'
abstract:
- lang: eng
  text: Neural-network classifiers achieve high accuracy when predicting the class
    of an input that they were trained to identify. Maintaining this accuracy in dynamic
    environments, where inputs frequently fall outside the fixed set of initially
    known classes, remains a challenge. We consider the problem of monitoring the
    classification decisions of neural networks in the presence of novel classes.
    For this purpose, we generalize our recently proposed abstraction-based monitor
    from binary output to real-valued quantitative output. This quantitative output
    enables new applications, two of which we investigate in the paper. As our first
    application, we introduce an algorithmic framework for active monitoring of a
    neural network, which allows us to learn new classes dynamically and yet maintain
    high monitoring performance. As our second application, we present an offline
    procedure to retrain the neural network to improve the monitor’s detection performance
    without deteriorating the network’s classification accuracy. Our experimental
    evaluation demonstrates both the benefits of our active monitoring framework in
    dynamic scenarios and the effectiveness of the retraining procedure.
acknowledgement: This work was supported in part by the ERC-2020-AdG 101020093, by
  DIREC - Digital Research Centre Denmark, and by the Villum Investigator Grant S4OS.
article_processing_charge: Yes (in subscription journal)
article_type: original
arxiv: 1
author:
- first_name: Konstantin
  full_name: Kueffner, Konstantin
  id: 8121a2d0-dc85-11ea-9058-af578f3b4515
  last_name: Kueffner
  orcid: 0000-0001-8974-2542
- first_name: Anna
  full_name: Lukina, Anna
  id: CBA4D1A8-0FE8-11E9-BDE6-07BFE5697425
  last_name: Lukina
- first_name: Christian
  full_name: Schilling, Christian
  id: 3A2F4DCE-F248-11E8-B48F-1D18A9856A87
  last_name: Schilling
  orcid: 0000-0003-3658-1065
- first_name: Thomas A
  full_name: Henzinger, Thomas A
  id: 40876CD8-F248-11E8-B48F-1D18A9856A87
  last_name: Henzinger
  orcid: 0000-0002-2985-7724
citation:
  ama: 'Kueffner K, Lukina A, Schilling C, Henzinger TA. Into the unknown: Active
    monitoring of neural networks (extended version). <i>International Journal on
    Software Tools for Technology Transfer</i>. 2023;25:575-592. doi:<a href="https://doi.org/10.1007/s10009-023-00711-4">10.1007/s10009-023-00711-4</a>'
  apa: 'Kueffner, K., Lukina, A., Schilling, C., &#38; Henzinger, T. A. (2023). Into
    the unknown: Active monitoring of neural networks (extended version). <i>International
    Journal on Software Tools for Technology Transfer</i>. Springer Nature. <a href="https://doi.org/10.1007/s10009-023-00711-4">https://doi.org/10.1007/s10009-023-00711-4</a>'
  chicago: 'Kueffner, Konstantin, Anna Lukina, Christian Schilling, and Thomas A Henzinger.
    “Into the Unknown: Active Monitoring of Neural Networks (Extended Version).” <i>International
    Journal on Software Tools for Technology Transfer</i>. Springer Nature, 2023.
    <a href="https://doi.org/10.1007/s10009-023-00711-4">https://doi.org/10.1007/s10009-023-00711-4</a>.'
  ieee: 'K. Kueffner, A. Lukina, C. Schilling, and T. A. Henzinger, “Into the unknown:
    Active monitoring of neural networks (extended version),” <i>International Journal
    on Software Tools for Technology Transfer</i>, vol. 25. Springer Nature, pp. 575–592,
    2023.'
  ista: 'Kueffner K, Lukina A, Schilling C, Henzinger TA. 2023. Into the unknown:
    Active monitoring of neural networks (extended version). International Journal
    on Software Tools for Technology Transfer. 25, 575–592.'
  mla: 'Kueffner, Konstantin, et al. “Into the Unknown: Active Monitoring of Neural
    Networks (Extended Version).” <i>International Journal on Software Tools for Technology
    Transfer</i>, vol. 25, Springer Nature, 2023, pp. 575–92, doi:<a href="https://doi.org/10.1007/s10009-023-00711-4">10.1007/s10009-023-00711-4</a>.'
  short: K. Kueffner, A. Lukina, C. Schilling, T.A. Henzinger, International Journal
    on Software Tools for Technology Transfer 25 (2023) 575–592.
date_created: 2023-07-16T22:01:11Z
date_published: 2023-08-01T00:00:00Z
date_updated: 2024-01-30T12:06:57Z
day: '01'
ddc:
- '000'
department:
- _id: ToHe
doi: 10.1007/s10009-023-00711-4
ec_funded: 1
external_id:
  arxiv:
  - '2009.06429'
  isi:
  - '001020160000001'
file:
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  date_created: 2024-01-30T12:06:07Z
  date_updated: 2024-01-30T12:06:07Z
  file_id: '14903'
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has_accepted_license: '1'
intvolume: '        25'
isi: 1
language:
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month: '08'
oa: 1
oa_version: Published Version
page: 575-592
project:
- _id: 62781420-2b32-11ec-9570-8d9b63373d4d
  call_identifier: H2020
  grant_number: '101020093'
  name: Vigilant Algorithmic Monitoring of Software
publication: International Journal on Software Tools for Technology Transfer
publication_identifier:
  eissn:
  - 1433-2787
  issn:
  - 1433-2779
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
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    status: public
scopus_import: '1'
status: public
title: 'Into the unknown: Active monitoring of neural networks (extended version)'
tmp:
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  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 25
year: '2023'
...
---
_id: '10206'
abstract:
- lang: eng
  text: Neural-network classifiers achieve high accuracy when predicting the class
    of an input that they were trained to identify. Maintaining this accuracy in dynamic
    environments, where inputs frequently fall outside the fixed set of initially
    known classes, remains a challenge. The typical approach is to detect inputs from
    novel classes and retrain the classifier on an augmented dataset. However, not
    only the classifier but also the detection mechanism needs to adapt in order to
    distinguish between newly learned and yet unknown input classes. To address this
    challenge, we introduce an algorithmic framework for active monitoring of a neural
    network. A monitor wrapped in our framework operates in parallel with the neural
    network and interacts with a human user via a series of interpretable labeling
    queries for incremental adaptation. In addition, we propose an adaptive quantitative
    monitor to improve precision. An experimental evaluation on a diverse set of benchmarks
    with varying numbers of classes confirms the benefits of our active monitoring
    framework in dynamic scenarios.
acknowledgement: We thank Christoph Lampert and Alex Greengold for fruitful discussions.
  This research was supported in part by the Simons Institute for the Theory of Computing,
  the Austrian Science Fund (FWF) under grant Z211-N23 (Wittgenstein Award), and the
  European Union’s Horizon 2020 research and innovation programme under the Marie
  Skłodowska-Curie grant agreement No. 754411.
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Anna
  full_name: Lukina, Anna
  id: CBA4D1A8-0FE8-11E9-BDE6-07BFE5697425
  last_name: Lukina
- first_name: Christian
  full_name: Schilling, Christian
  id: 3A2F4DCE-F248-11E8-B48F-1D18A9856A87
  last_name: Schilling
  orcid: 0000-0003-3658-1065
- first_name: Thomas A
  full_name: Henzinger, Thomas A
  id: 40876CD8-F248-11E8-B48F-1D18A9856A87
  last_name: Henzinger
  orcid: 0000-0002-2985-7724
citation:
  ama: 'Lukina A, Schilling C, Henzinger TA. Into the unknown: active monitoring of neural
    networks. In: <i>21st International Conference on Runtime Verification</i>. Vol
    12974. Cham: Springer Nature; 2021:42-61. doi:<a href="https://doi.org/10.1007/978-3-030-88494-9_3">10.1007/978-3-030-88494-9_3</a>'
  apa: 'Lukina, A., Schilling, C., &#38; Henzinger, T. A. (2021). Into the unknown:
    active monitoring of neural networks. In <i>21st International Conference on Runtime
    Verification</i> (Vol. 12974, pp. 42–61). Cham: Springer Nature. <a href="https://doi.org/10.1007/978-3-030-88494-9_3">https://doi.org/10.1007/978-3-030-88494-9_3</a>'
  chicago: 'Lukina, Anna, Christian Schilling, and Thomas A Henzinger. “Into the Unknown:
    Active Monitoring of Neural Networks.” In <i>21st International Conference on
    Runtime Verification</i>, 12974:42–61. Cham: Springer Nature, 2021. <a href="https://doi.org/10.1007/978-3-030-88494-9_3">https://doi.org/10.1007/978-3-030-88494-9_3</a>.'
  ieee: 'A. Lukina, C. Schilling, and T. A. Henzinger, “Into the unknown: active monitoring
    of neural networks,” in <i>21st International Conference on Runtime Verification</i>,
    Virtual, 2021, vol. 12974, pp. 42–61.'
  ista: 'Lukina A, Schilling C, Henzinger TA. 2021. Into the unknown: active monitoring
    of neural networks. 21st International Conference on Runtime Verification. RV:
    Runtime Verification, LNCS, vol. 12974, 42–61.'
  mla: 'Lukina, Anna, et al. “Into the Unknown: Active Monitoring of Neural Networks.”
    <i>21st International Conference on Runtime Verification</i>, vol. 12974, Springer
    Nature, 2021, pp. 42–61, doi:<a href="https://doi.org/10.1007/978-3-030-88494-9_3">10.1007/978-3-030-88494-9_3</a>.'
  short: A. Lukina, C. Schilling, T.A. Henzinger, in:, 21st International Conference
    on Runtime Verification, Springer Nature, Cham, 2021, pp. 42–61.
conference:
  end_date: 2021-10-14
  location: Virtual
  name: 'RV: Runtime Verification'
  start_date: 2021-10-11
date_created: 2021-10-31T23:01:31Z
date_published: 2021-10-06T00:00:00Z
date_updated: 2024-01-30T12:06:56Z
day: '06'
department:
- _id: ToHe
doi: 10.1007/978-3-030-88494-9_3
ec_funded: 1
external_id:
  arxiv:
  - '2009.06429'
  isi:
  - '000719383800003'
isi: 1
keyword:
- monitoring
- neural networks
- novelty detection
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/2009.06429
month: '10'
oa: 1
oa_version: Preprint
page: 42-61
place: Cham
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '754411'
  name: ISTplus - Postdoctoral Fellowships
- _id: 25F42A32-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z211
  name: The Wittgenstein Prize
publication: 21st International Conference on Runtime Verification
publication_identifier:
  eisbn:
  - 978-3-030-88494-9
  eissn:
  - 1611-3349
  isbn:
  - 9-783-0308-8493-2
  issn:
  - 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
related_material:
  record:
  - id: '13234'
    relation: extended_version
    status: public
scopus_import: '1'
status: public
title: 'Into the unknown: active monitoring of neural networks'
type: conference
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: '12974 '
year: '2021'
...
---
_id: '7505'
abstract:
- lang: eng
  text: Neural networks have demonstrated unmatched performance in a range of classification
    tasks. Despite numerous efforts of the research community, novelty detection remains
    one of the significant limitations of neural networks. The ability to identify
    previously unseen inputs as novel is crucial for our understanding of the decisions
    made by neural networks. At runtime, inputs not falling into any of the categories
    learned during training cannot be classified correctly by the neural network.
    Existing approaches treat the neural network as a black box and try to detect
    novel inputs based on the confidence of the output predictions. However, neural
    networks are not trained to reduce their confidence for novel inputs, which limits
    the effectiveness of these approaches. We propose a framework to monitor a neural
    network by observing the hidden layers. We employ a common abstraction from program
    analysis - boxes - to identify novel behaviors in the monitored layers, i.e.,
    inputs that cause behaviors outside the box. For each neuron, the boxes range
    over the values seen in training. The framework is efficient and flexible to achieve
    a desired trade-off between raising false warnings and detecting novel inputs.
    We illustrate the performance and the robustness to variability in the unknown
    classes on popular image-classification benchmarks.
acknowledgement: We thank Christoph Lampert and Nikolaus Mayer for fruitful discussions.
  This research was supported in part by the Austrian Science Fund (FWF) under grants
  S11402-N23 (RiSE/SHiNE) and Z211-N23 (Wittgenstein Award) and the European Union’s
  Horizon 2020 research and innovation programme under the Marie SkłodowskaCurie grant
  agreement No. 754411.
alternative_title:
- Frontiers in Artificial Intelligence and Applications
article_processing_charge: No
arxiv: 1
author:
- first_name: Thomas A
  full_name: Henzinger, Thomas A
  id: 40876CD8-F248-11E8-B48F-1D18A9856A87
  last_name: Henzinger
  orcid: 0000-0002-2985-7724
- first_name: Anna
  full_name: Lukina, Anna
  id: CBA4D1A8-0FE8-11E9-BDE6-07BFE5697425
  last_name: Lukina
- first_name: Christian
  full_name: Schilling, Christian
  id: 3A2F4DCE-F248-11E8-B48F-1D18A9856A87
  last_name: Schilling
  orcid: 0000-0003-3658-1065
citation:
  ama: 'Henzinger TA, Lukina A, Schilling C. Outside the box: Abstraction-based monitoring
    of neural networks. In: <i>24th European Conference on Artificial Intelligence</i>.
    Vol 325. IOS Press; 2020:2433-2440. doi:<a href="https://doi.org/10.3233/FAIA200375">10.3233/FAIA200375</a>'
  apa: 'Henzinger, T. A., Lukina, A., &#38; Schilling, C. (2020). Outside the box:
    Abstraction-based monitoring of neural networks. In <i>24th European Conference
    on Artificial Intelligence</i> (Vol. 325, pp. 2433–2440). Santiago de Compostela,
    Spain: IOS Press. <a href="https://doi.org/10.3233/FAIA200375">https://doi.org/10.3233/FAIA200375</a>'
  chicago: 'Henzinger, Thomas A, Anna Lukina, and Christian Schilling. “Outside the
    Box: Abstraction-Based Monitoring of Neural Networks.” In <i>24th European Conference
    on Artificial Intelligence</i>, 325:2433–40. IOS Press, 2020. <a href="https://doi.org/10.3233/FAIA200375">https://doi.org/10.3233/FAIA200375</a>.'
  ieee: 'T. A. Henzinger, A. Lukina, and C. Schilling, “Outside the box: Abstraction-based
    monitoring of neural networks,” in <i>24th European Conference on Artificial Intelligence</i>,
    Santiago de Compostela, Spain, 2020, vol. 325, pp. 2433–2440.'
  ista: 'Henzinger TA, Lukina A, Schilling C. 2020. Outside the box: Abstraction-based
    monitoring of neural networks. 24th European Conference on Artificial Intelligence.
    ECAI: European Conference on Artificial Intelligence, Frontiers in Artificial
    Intelligence and Applications, vol. 325, 2433–2440.'
  mla: 'Henzinger, Thomas A., et al. “Outside the Box: Abstraction-Based Monitoring
    of Neural Networks.” <i>24th European Conference on Artificial Intelligence</i>,
    vol. 325, IOS Press, 2020, pp. 2433–40, doi:<a href="https://doi.org/10.3233/FAIA200375">10.3233/FAIA200375</a>.'
  short: T.A. Henzinger, A. Lukina, C. Schilling, in:, 24th European Conference on
    Artificial Intelligence, IOS Press, 2020, pp. 2433–2440.
conference:
  end_date: 2020-09-08
  location: Santiago de Compostela, Spain
  name: 'ECAI: European Conference on Artificial Intelligence'
  start_date: 2020-08-29
date_created: 2020-02-21T16:44:03Z
date_published: 2020-02-24T00:00:00Z
date_updated: 2023-08-18T06:38:16Z
day: '24'
ddc:
- '000'
department:
- _id: ToHe
doi: 10.3233/FAIA200375
ec_funded: 1
external_id:
  arxiv:
  - '1911.09032'
  isi:
  - '000650971303002'
file:
- access_level: open_access
  checksum: 80642fa0b6cd7da95dcd87d63789ad5e
  content_type: application/pdf
  creator: dernst
  date_created: 2020-09-21T07:12:32Z
  date_updated: 2020-09-21T07:12:32Z
  file_id: '8540'
  file_name: 2020_ECAI_Henzinger.pdf
  file_size: 1692214
  relation: main_file
  success: 1
file_date_updated: 2020-09-21T07:12:32Z
has_accepted_license: '1'
intvolume: '       325'
isi: 1
language:
- iso: eng
license: https://creativecommons.org/licenses/by-nc/4.0/
month: '02'
oa: 1
oa_version: Published Version
page: 2433-2440
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '754411'
  name: ISTplus - Postdoctoral Fellowships
- _id: 25832EC2-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: S 11407_N23
  name: Rigorous Systems Engineering
- _id: 25F42A32-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z211
  name: The Wittgenstein Prize
publication: 24th European Conference on Artificial Intelligence
publication_status: published
publisher: IOS Press
quality_controlled: '1'
status: public
title: 'Outside the box: Abstraction-based monitoring of neural networks'
tmp:
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type: conference
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 325
year: '2020'
...
---
_id: '9040'
abstract:
- lang: eng
  text: Machine learning and formal methods have complimentary benefits and drawbacks.
    In this work, we address the controller-design problem with a combination of techniques
    from both fields. The use of black-box neural networks in deep reinforcement learning
    (deep RL) poses a challenge for such a combination. Instead of reasoning formally
    about the output of deep RL, which we call the wizard, we extract from it a decision-tree
    based model, which we refer to as the magic book. Using the extracted model as
    an intermediary, we are able to handle problems that are infeasible for either
    deep RL or formal methods by themselves. First, we suggest, for the first time,
    a synthesis procedure that is based on a magic book. We synthesize a stand-alone
    correct-by-design controller that enjoys the favorable performance of RL. Second,
    we incorporate a magic book in a bounded model checking (BMC) procedure. BMC allows
    us to find numerous traces of the plant under the control of the wizard, which
    a user can use to increase the trustworthiness of the wizard and direct further
    training.
acknowledgement: This research was supported in part by the Austrian Science Fund
  (FWF) under grant Z211-N23 (Wittgenstein Award).
article_processing_charge: No
author:
- first_name: Par Alizadeh
  full_name: Alamdari, Par Alizadeh
  last_name: Alamdari
- first_name: Guy
  full_name: Avni, Guy
  id: 463C8BC2-F248-11E8-B48F-1D18A9856A87
  last_name: Avni
  orcid: 0000-0001-5588-8287
- first_name: Thomas A
  full_name: Henzinger, Thomas A
  id: 40876CD8-F248-11E8-B48F-1D18A9856A87
  last_name: Henzinger
  orcid: 0000-0002-2985-7724
- first_name: Anna
  full_name: Lukina, Anna
  id: CBA4D1A8-0FE8-11E9-BDE6-07BFE5697425
  last_name: Lukina
citation:
  ama: 'Alamdari PA, Avni G, Henzinger TA, Lukina A. Formal methods with a touch of
    magic. In: <i>Proceedings of the 20th Conference on Formal Methods in Computer-Aided
    Design</i>. TU Wien Academic Press; 2020:138-147. doi:<a href="https://doi.org/10.34727/2020/isbn.978-3-85448-042-6_21">10.34727/2020/isbn.978-3-85448-042-6_21</a>'
  apa: 'Alamdari, P. A., Avni, G., Henzinger, T. A., &#38; Lukina, A. (2020). Formal
    methods with a touch of magic. In <i>Proceedings of the 20th Conference on Formal
    Methods in Computer-Aided Design</i> (pp. 138–147). Online Conference: TU Wien
    Academic Press. <a href="https://doi.org/10.34727/2020/isbn.978-3-85448-042-6_21">https://doi.org/10.34727/2020/isbn.978-3-85448-042-6_21</a>'
  chicago: Alamdari, Par Alizadeh, Guy Avni, Thomas A Henzinger, and Anna Lukina.
    “Formal Methods with a Touch of Magic.” In <i>Proceedings of the 20th Conference
    on Formal Methods in Computer-Aided Design</i>, 138–47. TU Wien Academic Press,
    2020. <a href="https://doi.org/10.34727/2020/isbn.978-3-85448-042-6_21">https://doi.org/10.34727/2020/isbn.978-3-85448-042-6_21</a>.
  ieee: P. A. Alamdari, G. Avni, T. A. Henzinger, and A. Lukina, “Formal methods with
    a touch of magic,” in <i>Proceedings of the 20th Conference on Formal Methods
    in Computer-Aided Design</i>, Online Conference, 2020, pp. 138–147.
  ista: 'Alamdari PA, Avni G, Henzinger TA, Lukina A. 2020. Formal methods with a
    touch of magic. Proceedings of the 20th Conference on Formal Methods in Computer-Aided
    Design.  FMCAD: Formal Methods in Computer-Aided Design, 138–147.'
  mla: Alamdari, Par Alizadeh, et al. “Formal Methods with a Touch of Magic.” <i>Proceedings
    of the 20th Conference on Formal Methods in Computer-Aided Design</i>, TU Wien
    Academic Press, 2020, pp. 138–47, doi:<a href="https://doi.org/10.34727/2020/isbn.978-3-85448-042-6_21">10.34727/2020/isbn.978-3-85448-042-6_21</a>.
  short: P.A. Alamdari, G. Avni, T.A. Henzinger, A. Lukina, in:, Proceedings of the
    20th Conference on Formal Methods in Computer-Aided Design, TU Wien Academic Press,
    2020, pp. 138–147.
conference:
  end_date: 2020-09-24
  location: Online Conference
  name: ' FMCAD: Formal Methods in Computer-Aided Design'
  start_date: 2020-09-21
date_created: 2021-01-24T23:01:10Z
date_published: 2020-09-21T00:00:00Z
date_updated: 2021-02-09T09:39:59Z
day: '21'
ddc:
- '000'
department:
- _id: ToHe
doi: 10.34727/2020/isbn.978-3-85448-042-6_21
file:
- access_level: open_access
  checksum: d616d549a0ade78606b16f8a9540820f
  content_type: application/pdf
  creator: dernst
  date_created: 2021-02-09T09:39:02Z
  date_updated: 2021-02-09T09:39:02Z
  file_id: '9109'
  file_name: 2020_FMCAD_Alamdari.pdf
  file_size: 990999
  relation: main_file
  success: 1
file_date_updated: 2021-02-09T09:39:02Z
has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: 138-147
project:
- _id: 25F42A32-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z211
  name: The Wittgenstein Prize
publication: Proceedings of the 20th Conference on Formal Methods in Computer-Aided
  Design
publication_identifier:
  eissn:
  - 2708-7824
  isbn:
  - '9783854480426'
publication_status: published
publisher: TU Wien Academic Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Formal methods with a touch of magic
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  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2020'
...
