parameters: (cls, name, bases, dictionary)
docstring: Creates a message service class.
  
      Args:
        name: Name of the class (ignored, but required by the metaclass
          protocol).
        bases: Base classes of the class being constructed.
        dictionary: The class dictionary of the class being constructed.
          dictionary[_DESCRIPTOR_KEY] must contain a ServiceDescriptor object
          describing this protocol service type.
docstring_summary: Creates a message service class.
docstring_tokens: Creates a message service class .
function: def __init__(cls, name, bases, dictionary):
      """Creates a message service class.
  
      Args:
        name: Name of the class (ignored, but required by the metaclass
          protocol).
        bases: Base classes of the class being constructed.
        dictionary: The class dictionary of the class being constructed.
          dictionary[_DESCRIPTOR_KEY] must contain a ServiceDescriptor object
          describing this protocol service type.
      """
      # Don't do anything if this class doesn't have a descriptor. This happens
      # when a service class is subclassed.
      if GeneratedServiceType._DESCRIPTOR_KEY not in dictionary:
        return
      descriptor = dictionary[GeneratedServiceType._DESCRIPTOR_KEY]
      service_builder = _ServiceBuilder(descriptor)
      service_builder.BuildService(cls)
function_tokens: def __init__ ( cls , name , bases , dictionary ) : # Don't do anything if this class doesn't have a descriptor. This happens # when a service class is subclassed. if GeneratedServiceType . _DESCRIPTOR_KEY not in dictionary : return descriptor = dictionary [ GeneratedServiceType . _DESCRIPTOR_KEY ] service_builder = _ServiceBuilder ( descriptor ) service_builder . BuildService ( cls )