'Ensure that errors in struct definitions are raised.'

def testStructDefinition(self):

    self.assertRaises(type_info.TypeValueError, structs.ProtoEmbedded, name='name')
    self.assertRaises(type_info.TypeValueError, TestStruct.AddDescriptor, structs.ProtoUnsignedInteger(name='int', field_number=2))
    self.assertRaises(type_info.TypeValueError, TestStruct.AddDescriptor, type_info.String(name='int'))
