public function get_present_plugins($type) {
        $this->load_present_plugins();
        if (isset($this->presentplugins[$type])) {
            return $this->presentplugins[$type];
        }
        return null;
    }
public function get_present_plugins($type) {
        $this->load_present_plugins();
        if (isset($this->presentplugins[$type])) {
            return $this->presentplugins[$type];
        }
        return null;
    }
public function get_present_plugins ( $ type ) { $ this -> load_present_plugins ( ) ; if ( isset ( $ this -> presentplugins [ $ type ] ) ) { return $ this -> presentplugins [ $ type ] ; } return null ; }
Get list of present plugins of given type.

@param string $type
@return array|null  list of presnet plugins $name=>$diskversion, null if unknown
Get list of present plugins of given type .