def set_provider(self, provider_id=None):
pass<EOL>
Sets a provider.

        arg:    provider_id (osid.id.Id): the new provider
        raise:  InvalidArgument - ``provider_id`` is invalid
        raise:  NoAccess - ``Metadata.isReadOnly()`` is ``true``
        raise:  NullArgument - ``provider_id`` is ``null``
        *compliance: mandatory -- This method must be implemented.*