Tags each `Residues` Polymer with its solvent accessibility.

        Notes
        -----
        For more about DSSP's solvent accessibilty metric, see:
            http://swift.cmbi.ru.nl/gv/dssp/HTML/descrip.html#ACC

        References
        ----------
        .. [1] Kabsch W, Sander C (1983) "Dictionary of protein
           secondary structure: pattern recognition of hydrogen-bonded
           and geometrical features", Biopolymers, 22, 2577-637.

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

def tag_dssp_solvent_accessibility(self, force=False):
        """Tags each `Residues` Polymer with its solvent accessibility.

        Notes
        -----
        For more about DSSP's solvent accessibilty metric, see:
            http://swift.cmbi.ru.nl/gv/dssp/HTML/descrip.html#ACC

        References
        ----------
        .. [1] Kabsch W, Sander C (1983) "Dictionary of protein
           secondary structure: pattern recognition of hydrogen-bonded
           and geometrical features", Biopolymers, 22, 2577-637.

        Parameters
        ----------
        force : bool, optional
            If `True` the tag will be run even if `Residues` are
            already tagged.
        """
        tagged = ['dssp_acc' in x.tags.keys() for x in self._monomers]
        if (not all(tagged)) or force:
            dssp_out = run_dssp(self.pdb, path=False)
            if dssp_out is None:
                return
            dssp_acc_list = extract_solvent_accessibility_dssp(
                dssp_out, path=False)
            for monomer, dssp_acc in zip(self._monomers, dssp_acc_list):
                monomer.tags['dssp_acc'] = dssp_acc[-1]
        return