def __call__(self, tex_source):
for linker in self._linkers:<EOL><INDENT>tex_source = linker(tex_source)<EOL><DEDENT>return tex_source<EOL>
r"""Convert citations in LaTeX source to Hyperref links.

        Parameters
        ----------
        tex_source : `str`
            LaTeX document source.

        Returns
        -------
        processed_tex : `str`
            LaTeX document source with all citation commands converted to
            ``\hyperref`` commands.