public function get_sketch_data($start, $end, $variable=null, $resolution=null, $plugin_name=null, $plugin_type=null) {
		$params = array('id' => $this->id, 'start' => $start, 'end' => $end);
		if($variable) { $params['variable'] = $variable; }
		if($resolution) { $params['resolution'] = $resolution; }
		if($plugin_name) { $params['plugin_name'] = $plugin_name; }
		if($plugin_type) { $params['plugin_type'] = $plugin_type; }
		$result = $this->executeCommand($this->_path_for_regex . '_get_sketchy_data', $params);
		$json_str = $result->getBody(true);
		$json_obj = json_decode($json_str);
		return $json_obj;		
	}