code: def AddServiceDescriptor(self, service_desc):
      
  
      if not isinstance(service_desc, descriptor.ServiceDescriptor):
        raise TypeError('Expected instance of descriptor.ServiceDescriptor.')
  
      self._service_descriptors[service_desc.full_name] = service_desc
docs: Adds a ServiceDescriptor to the pool.
  
      Args:
        service_desc: A ServiceDescriptor.