src/Reporter/Coverage/Collector.php
public function start()
    {
        if ($collector = end(static::$_collectors)) {
            $collector->add($collector->_driver->stop());
        }
        static::$_collectors[] = $this;
        $this->_driver->start();
        return true;
    }
public function start()
    {
        if ($collector = end(static::$_collectors)) {
            $collector->add($collector->_driver->stop());
        }
        static::$_collectors[] = $this;
        $this->_driver->start();
        return true;
    }
public function start ( ) { if ( $ collector = end ( static :: $ _collectors ) ) { $ collector -> add ( $ collector -> _driver -> stop ( ) ) ; } static :: $ _collectors [ ] = $ this ; $ this -> _driver -> start ( ) ; return true ; }
Starts collecting coverage data.

@return boolean
Starts collecting coverage data .