The residue numbers of the protein can be reformated in case of misallignment with the convention.
            Takes:
                 * offset * - a number that represents by how many residues the numbering has to be shifted.

def renumber_system(self, offset):
        """
        The residue numbers of the protein can be reformated in case of misallignment with the convention.
            Takes:
                 * offset * - a number that represents by how many residues the numbering has to be shifted.
        """

        self.universe.protein = self.universe.select_atoms("protein")
        self.universe.protein.residues.resids = self.universe.protein.residues.resids+int(offset)