public static function exists(string $func): bool
    {
        if (strpos($func, "::") !== false) {
            list($class, $method) = explode("::", $func);
            return method_exists($class, $method);
        }
        return function_exists($func);
    }
public static function exists(string $func): bool
    {
        if (strpos($func, "::") !== false) {
            list($class, $method) = explode("::", $func);
            return method_exists($class, $method);
        }
        return function_exists($func);
    }
public static function exists ( string $ func ) : bool { if ( strpos ( $ func , "::" ) !== false ) { list ( $ class , $ method ) = explode ( "::" , $ func ) ; return method_exists ( $ class , $ method ) ; } return function_exists ( $ func ) ; }
Verify a callable provided as a string

@param string $func The callable to verify
@return bool
Verify a callable provided as a string