code: def tf_name_scope(self):
          
          if self.parent is self:
              leader_name = self.name
              leader_index = self.index
              if leader_index is None:
                  return leader_name
              return "{name}-{index}".format(name=leader_name, index=leader_index)
          return self.pathname.rsplit('/')[-1]
docs: Auxilary method for composing gpflow's tree name scopes. The Parentable pathname
          can be considered as a set of name scopes. This method grabs `pathname` and
          returns only name of the node in that path.
          Leading node name is always replaced with two parts: the name and the index
          for uniquiness in TensorFlow.