def __init__(self, unexpected_method, expected):
    """Init exception.

    Args:
      # unexpected_method: MockMethod that was called but was not at the head of
      #   the expected_method queue.
      # expected: MockMethod or UnorderedGroup the method should have
      #   been in.
      unexpected_method: MockMethod
      expected: MockMethod or UnorderedGroup
    """

    Error.__init__(self)
    if expected is None:
      self._str = "Unexpected method call %s" % (unexpected_method,)
    else:
      differ = difflib.Differ()
      diff = differ.compare(str(unexpected_method).splitlines(True),
                            str(expected).splitlines(True))
      self._str = ("Unexpected method call.  unexpected:-  expected:+\n%s"
                   % ("\n".join(diff),))
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/mox/mox.py/UnexpectedMethodCallError.__init__/original