src/Matcher.php
public static function exists($name, $target = '')
    {
        if ($target === true) {
            return isset(static::$_matchers[$name]);
        }
        return isset(static::$_matchers[$name][$target]);
    }
public static function exists($name, $target = '')
    {
        if ($target === true) {
            return isset(static::$_matchers[$name]);
        }
        return isset(static::$_matchers[$name][$target]);
    }
public static function exists ( $ name , $ target = '' ) { if ( $ target === true ) { return isset ( static :: $ _matchers [ $ name ] ) ; } return isset ( static :: $ _matchers [ $ name ] [ $ target ] ) ; }
Checks if a matcher is registered.

@param  string $name   The name of the matcher.
@param  string $target An optional target class name.

@return boolean         Returns `true` if the matcher exists, `false` otherwise.
Checks if a matcher is registered .