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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def AddServiceDescriptor(self, service_desc):
 """Adds a ServiceDescriptor to the pool. Args: service_desc: A ServiceDescriptor. """


    if not isinstance(service_desc, descriptor.ServiceDescriptor):
      raise TypeError('Expected instance of descriptor.ServiceDescriptor.')

    self._service_descriptors[service_desc.full_name] = service_desc