protected function prepare_item_for_database( $request ) {

		$prepared = array();
		$map      = $this->map_schema_to_database();
		$schema   = $this->get_item_schema();

		foreach ( $map as $req_key => $db_key ) {
			if ( ! empty( $request[ $req_key ] ) ) {
				$prepared[ $db_key ] = $request[ $req_key ];
			}
		}

		return $prepared;
	}