/**
  * @see \str\substring() substring
  */
 public static function substring($string_, $offset_, $length_ = null)
 {
     return \str\substring($string_, $offset_, $length_);
 }
 public function __call($name_, array $args_ = [])
 {
     // TODO Defined routine.
     if (0 === strpos($name_, 'is')) {
         if (0 === strnatcasecmp(substr($name_, 2), str_replace('/', '', $this->m_name))) {
             return true;
         }
         $name = \str\camelCaseToUnderscore($name_);
         $name = \str\substring($name, 3);
         $chunks = explode('_', $name);
         if (1 === count($chunks)) {
             return 0 === \str\compareIgnoreCase($chunks[0], $this->type());
         }
         return false;
     }
     throw new Exception_NotImplemented('io/mimetype', sprintf('Call to undefined method %s::%s() in %s on line %d.', $type, $name_, $caller['file'], $caller['line']));
 }