Get a single Role by name.

        Args:
            name (str): The name of the Role.

        Returns:
            (:obj:`Role`): The Role that matches the name or None.

def get_role(self, name):
        """Get a single Role by name.

        Args:
            name (str): The name of the Role.

        Returns:
            (:obj:`Role`): The Role that matches the name or None.
        """

        address = _create_role_address(name)
        role_list_bytes = None

        try:
            role_list_bytes = self._state_view.get(address=address)
        except KeyError:
            return None

        if role_list_bytes is not None:
            role_list = _create_from_bytes(role_list_bytes,
                                           identity_pb2.RoleList)
            for role in role_list.roles:
                if role.name == name:
                    return role
        return None