original_string: public static function extend( $placeholder, array $selectors ) {
  		if ( ! isset( static::$placeholders[ $placeholder ] ) ) {
  			static::$placeholders[ $placeholder ] = [];
  		}
  
  		static::$placeholders[ $placeholder ] = array_merge(
  			static::$placeholders[ $placeholder ],
  			$selectors
  		);
  	}
code: public static function extend( $placeholder, array $selectors ) {
  		if ( ! isset( static::$placeholders[ $placeholder ] ) ) {
  			static::$placeholders[ $placeholder ] = [];
  		}
  
  		static::$placeholders[ $placeholder ] = array_merge(
  			static::$placeholders[ $placeholder ],
  			$selectors
  		);
  	}
code_tokens: public static function extend ( $ placeholder , array $ selectors ) { if ( ! isset ( static :: $ placeholders [ $ placeholder ] ) ) { static :: $ placeholders [ $ placeholder ] = [ ] ; } static :: $ placeholders [ $ placeholder ] = array_merge ( static :: $ placeholders [ $ placeholder ] , $ selectors ) ; }
docstring: Set selectors. Styles of these selectors output like extend of Sass.
  
  @param string $placeholder
  @param array $selectors
  @return void
docstring_tokens: Set selectors . Styles of these selectors output like extend of Sass .