public function before(\Closure $closure = null)
    {
        if (null !== $closure) {
            $this->before[] = $closure;

            return $this;
        }

        return $this->before[] = new ExprBuilder($this->node);
    }
public function before(\Closure $closure = null)
    {
        if (null !== $closure) {
            $this->before[] = $closure;

            return $this;
        }

        return $this->before[] = new ExprBuilder($this->node);
    }
public function before ( \ Closure $ closure = null ) { if ( null !== $ closure ) { $ this -> before [ ] = $ closure ; return $ this ; } return $ this -> before [ ] = new ExprBuilder ( $ this -> node ) ; }
Registers a closure to run before the normalization or an expression builder to build it if null is provided.

@return ExprBuilder|$this
Registers a closure to run before the normalization or an expression builder to build it if null is provided .