Tags each `Monomer` in the `Assembly` with its torsion angles.

        Parameters
        ----------
        force : bool, optional
            If `True`, the tag will be run even if `Monomers` are already
            tagged.

def tag_torsion_angles(self, force=False):
        """Tags each `Monomer` in the `Assembly` with its torsion angles.

        Parameters
        ----------
        force : bool, optional
            If `True`, the tag will be run even if `Monomers` are already
            tagged.
        """
        for polymer in self._molecules:
            if polymer.molecule_type == 'protein':
                polymer.tag_torsion_angles(force=force)
        return