/**
  * create a proxy for an Ext.Component that is contained within an other
  * 
  * @param Ext_Component $_parent        proxy for the container Ext component
  * @param String        $_expression    JavaScript expression that evaluates this proxy's component on that of the container
  * @return void
  */
 public function __construct($_parent, $_expression, $_selenium = NULL)
 {
     $this->_parent = $_parent;
     $this->_expression = $_expression;
     $this->_selenium = $_selenium ? $_selenium : $_parent->getSelenium();
 }
 public function __construct($_parent, $_text)
 {
     parent::__construct($_parent, ".findBy(function(component) {" . "return (component.isXType && component.isXType('button'))" . "&& (component.text && component.text == '" . $_text . "')" . "})[0]");
 }