Tags each Monomer of the Polymer with its omega, phi and psi torsion angle.

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

def tag_torsion_angles(self, force=False):
        """Tags each Monomer of the Polymer with its omega, phi and psi torsion angle.

        Parameters
        ----------
        force : bool, optional
            If `True` the tag will be run even if `Residues` are
            already tagged.
        """
        tagged = ['omega' in x.tags.keys() for x in self._monomers]
        if (not all(tagged)) or force:
            tas = measure_torsion_angles(self._monomers)
            for monomer, (omega, phi, psi) in zip(self._monomers, tas):
                monomer.tags['omega'] = omega
                monomer.tags['phi'] = phi
                monomer.tags['psi'] = psi
                monomer.tags['tas'] = (omega, phi, psi)
        return