'Returns a dict of {<method-name>: (<request-type>, <response-type>)}.'

@classmethod
def _MethodSignatures(cls):

    return {'BeginTransaction': (BeginTransactionRequest, BeginTransactionResponse), 'Rollback': (RollbackRequest, RollbackResponse), 'Commit': (CommitRequest, CommitResponse), 'RunQuery': (RunQueryRequest, RunQueryResponse), 'ContinueQuery': (ContinueQueryRequest, ContinueQueryResponse), 'Lookup': (LookupRequest, LookupResponse), 'AllocateIds': (AllocateIdsRequest, AllocateIdsResponse)}
