Mocking boto exception

I was getting so frustrated.

I knew how to raise the exception with side_effect=. But, how do you mock the exception?

    connection = connect_to_sqs
except BotoServerError as m:
    if m.error_code == "AlreadyExistsException"

To get it to work, I inherited the exception class – BotoServerError

from boto.exceptions import BotoServerError

class MockBotoServerError(BotoServerError):
    def __init__(self, error_code)
        self.error_code = error_code

@mock.patch('', side_effect=MockBotoServerError())

Order of decorator

Also, pay attention to the order of parameters. My assertions were failing left and right.