docs: def apply_docstr(docstr_func):
      """
      Changes docstr of one functio to that of another
      """
      def docstr_applier(func):
          #docstr = meta_util_six.get_funcdoc(docstr_func)
          #meta_util_six.set_funcdoc(func, docstr)
          if isinstance(docstr_func, six.string_types):
              olddoc = meta_util_six.get_funcdoc(func)
              if olddoc is None:
                  olddoc = ''
              newdoc = olddoc + docstr_func
              meta_util_six.set_funcdoc(func, newdoc)
              return func
          else:
              preserved_func = preserve_sig(func, docstr_func)
              return preserved_func
      return docstr_applier