code/libraries/joomlatools/library/object/identifier/identifier.php
public function __isset($property)
    {
        $name = ltrim($property, '_');
        $vars = get_object_vars($this);

        return isset($vars['_'.$name]);
    }
public function __isset($property)
    {
        $name = ltrim($property, '_');
        $vars = get_object_vars($this);

        return isset($vars['_'.$name]);
    }
public function __isset ( $ property ) { $ name = ltrim ( $ property , '_' ) ; $ vars = get_object_vars ( $ this ) ; return isset ( $ vars [ '_' . $ name ] ) ; }
This function checks if a virtual property is set.

@param   string  $property The virtual property to return.
@return  boolean True if it exists otherwise false.
This function checks if a virtual property is set .