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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_roles(self):
 """Return all the Roles under the Identity namespace. Returns: (list):
 A list containing all the Roles under the Identity namespace. """


        prefix = _IDENTITY_NS + _ROLE_NS
        rolelist_list = [
            _create_from_bytes(d, identity_pb2.RoleList)
            for _, d in self._state_view.leaves(prefix=prefix)
        ]
        roles = []
        for role_list in rolelist_list:
            for role in role_list.roles:
                roles.append(role)
        return sorted(roles, key=lambda r: r.name)