'Return the mathematical coset table of ``self`` in ``H``.'

def coset_table(self, H, strategy='relator_based'):

    if (not H):
        if (self._coset_table != None):
            if (not self._is_standardized):
                self.standardize_coset_table()
        else:
            C = self.coset_enumeration([], strategy)
            self._coset_table = C
            self.standardize_coset_table()
        return self._coset_table.table
    else:
        C = self.coset_enumeration(H, strategy)
        C.standardize()
        return C.table
