wikimedia / mediawiki

	 * @return bool|string

	 */

	public function generateContentDiffBody( Content $old, Content $new ) {

		if ( !( $old instanceof TextContent ) ) {

			throw new MWException( "Diff not implemented for " . get_class( $old ) . "; " .

				"override generateContentDiffBody to fix this." );

		}

		if ( !( $new instanceof TextContent ) ) {

			throw new MWException( "Diff not implemented for " . get_class( $new ) . "; "

				"override generateContentDiffBody to fix this." );

		}

		if ( !( $new instanceof TextContent ) ) {

			throw new MWException( "Diff not implemented for " . get_class( $new ) . "; "

				. "override generateContentDiffBody to fix this." );

		}

		$otext = $old->serialize();

		$ntext = $new->serialize();