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

        arg:    providerId (osid.id.Id): the new provider
        raise:  INVALID_ARGUMENT - providerId is invalid
        raise:  NO_ACCESS - metadata.is_read_only() is true
        raise:  NULL_ARGUMENT - providerId is null
        compliance: mandatory - This method must be implemented.