code: def copy(self, other):
          
          # copy from other to self
          self.data.update(other.data)
          if other.comment is not None:
              self.comment = other.comment
          return self
docs: Copy metadata from another :py:class:`Metadata` object.
  
          Returns the :py:class:`Metadata` object, allowing convenient
          code like this::
  
              md = Metadata().copy(other_md)
  
          :param Metadata other: The metadata to copy.
  
          :rtype: :py:class:`Metadata`