text: from datetime import datetime
  
  mock_constants = {
      "DATE_TIME_MOCK_OBJ": datetime(2015, 1, 1)
  }
  
  def mocked_aws_step_function(*args, **kwargs):
      class MockAwsStepFunction:
          def __init__(self, aws_access_key_id, aws_secret_access_key, region_name):
              """Mock init; does nothing"""
              pass
  
          def get_execution_result(self, execution_arn):
              """Mock function that returns details about an ongoing execution description"""
              if execution_arn == "0000":
                  startDate = mock_constants.get("DATE_TIME_MOCK_OBJ")
                  stopDate = mock_constants.get("DATE_TIME_MOCK_OBJ")
              elif execution_arn == "1111":
                  startDate = mock_constants.get("DATE_TIME_MOCK_OBJ")
                  stopDate = None
  
              return {
                  # response formatted from 
                  # https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/stepfunctions.html#SFN.Client.describe_execution
                  'startDate': startDate,
                  'stopDate': stopDate,
              }
  
          def invoke_step_function(self, step_function_name, async_bool, payload):
              return self.get_execution_result(step_function_name)
  
      return MockAwsStepFunction(*args, **kwargs)
  
  def mocked_aws_lambda(*args, **kwargs):
      class MockAWSLambda:
          def __init__(self, aws_access_key_id, aws_secret_access_key, region_name):
              """Mock init; does nothing"""
              pass
  
          def invoke_lambda(self, function_name, payload):
              """Mock invocation of AWS lambda"""
              if function_name == "two_int_sum":
                  val = int(payload.get("x")) + int(payload.get("y"))
              elif function_name == "concat_strings":
                  val = payload.get("str1") + payload.get("str2")
  
              return {
                  # response json formatted from 
                  # https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/lambda.html#Lambda.Client.invoke
                  'StatusCode': 200,
                  'FunctionError': 'MockedFunctionError',
                  'LogResult': 'MockedLogResult',
                  'Payload': _MockResponse(val),
                  'ExecutedVersion': 'nan'
              }
  
      class _MockResponse:
          def __init__(self, val):
              self.val = bytes(str(val), 'utf-8')
          
          def read(self):
              return self.val
  
      return MockAWSLambda(*args, **kwargs)
  
  def mocked_aws_sns(*args, **kwargs):
      class AwsSns:
          def __init__(self, aws_access_key_id, aws_secret_access_key, region_name, topic_name):
              pass
  
          def send_text_via_sns(self, message, cell_numbers):
              return {
                  # https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/sns.html#SNS.Client.publish
                  'MessageId': '0000',
                  'SequenceNumber': 'None'
              }
      
      return AwsSns(*args, **kwargs)
  