Returns the key to use for the docblock immediately preceding
        the specified line.

def _docstring_key(self, line):
        """Returns the key to use for the docblock immediately preceding
        the specified line."""
        decormatch = self.docparser.RE_DECOR.match(line)
        if decormatch is not None:
            key = "{}.{}".format(self.docelement.name, decormatch.group("name"))
        else:
            key = self.element.name

        return key