PO::match_begin_and_end_newlines( $translation,  $original )

	public static function match_begin_and_end_newlines( $translation, $original ) {
		if ( '' === $translation ) {
			return $translation;
		}

		$original_begin = "\n" === substr( $original, 0, 1 );
		$original_end = "\n" === substr( $original, -1 );
		$translation_begin = "\n" === substr( $translation, 0, 1 );
		$translation_end = "\n" === substr( $translation, -1 );

		if ( $original_begin ) {
			if ( ! $translation_begin ) {
				$translation = "\n" . $translation;
			}
		} elseif ( $translation_begin ) {
			$translation = ltrim( $translation, "\n" );
		}

		if ( $original_end ) {
			if ( ! $translation_end ) {
				$translation .= "\n";
			}
		} elseif ( $translation_end ) {
			$translation = rtrim( $translation, "\n" );
		}

		return $translation;
	}