def describe_assessment_runs(assessmentRunArns=None):
    """
    Describes the assessment runs that are specified by the ARNs of the assessment runs.
    See also: AWS API Documentation
    
    Examples
    Describes the assessment runs that are specified by the ARNs of the assessment runs.
    Expected Output:
    
    :example: response = client.describe_assessment_runs(
        assessmentRunArns=[
            'string',
        ]
    )
    
    
    :type assessmentRunArns: list
    :param assessmentRunArns: [REQUIRED]
            The ARN that specifies the assessment run that you want to describe.
            (string) --
            

    :rtype: dict
    :return: {
        'assessmentRuns': [
            {
                'arn': 'string',
                'name': 'string',
                'assessmentTemplateArn': 'string',
                'state': 'CREATED'|'START_DATA_COLLECTION_PENDING'|'START_DATA_COLLECTION_IN_PROGRESS'|'COLLECTING_DATA'|'STOP_DATA_COLLECTION_PENDING'|'DATA_COLLECTED'|'START_EVALUATING_RULES_PENDING'|'EVALUATING_RULES'|'FAILED'|'ERROR'|'COMPLETED'|'COMPLETED_WITH_ERRORS',
                'durationInSeconds': 123,
                'rulesPackageArns': [
                    'string',
                ],
                'userAttributesForFindings': [
                    {
                        'key': 'string',
                        'value': 'string'
                    },
                ],
                'createdAt': datetime(2015, 1, 1),
                'startedAt': datetime(2015, 1, 1),
                'completedAt': datetime(2015, 1, 1),
                'stateChangedAt': datetime(2015, 1, 1),
                'dataCollected': True|False,
                'stateChanges': [
                    {
                        'stateChangedAt': datetime(2015, 1, 1),
                        'state': 'CREATED'|'START_DATA_COLLECTION_PENDING'|'START_DATA_COLLECTION_IN_PROGRESS'|'COLLECTING_DATA'|'STOP_DATA_COLLECTION_PENDING'|'DATA_COLLECTED'|'START_EVALUATING_RULES_PENDING'|'EVALUATING_RULES'|'FAILED'|'ERROR'|'COMPLETED'|'COMPLETED_WITH_ERRORS'
                    },
                ],
                'notifications': [
                    {
                        'date': datetime(2015, 1, 1),
                        'event': 'ASSESSMENT_RUN_STARTED'|'ASSESSMENT_RUN_COMPLETED'|'ASSESSMENT_RUN_STATE_CHANGED'|'FINDING_REPORTED'|'OTHER',
                        'message': 'string',
                        'error': True|False,
                        'snsTopicArn': 'string',
                        'snsPublishStatusCode': 'SUCCESS'|'TOPIC_DOES_NOT_EXIST'|'ACCESS_DENIED'|'INTERNAL_ERROR'
                    },
                ],
                'findingCounts': {
                    'string': 123
                }
            },
        ],
        'failedItems': {
            'string': {
                'failureCode': 'INVALID_ARN'|'DUPLICATE_ARN'|'ITEM_DOES_NOT_EXIST'|'ACCESS_DENIED'|'LIMIT_EXCEEDED'|'INTERNAL_ERROR',
                'retryable': True|False
            }
        }
    }
    
    
    :returns: 
    (string) --
    
    """
    pass
