Creating a boto3 ClientError manually!

custom_client_error_boto3.py

raise ClientError(operation_name='InvalidKeyPair.Duplicate', error_response={
    'Error': {
        'Code': 'Duplicate', 
        'Message': 'This is a custom message'
       }
     }
)

This is not recommended but rather let the boto3 sdk return the appropriate exceptions

Only use I can think of is you have custom exceptions ...

Thank you, this was really helpful for creating a MagicMock side effect