code: public function getBasePath()
      {
          if ($this->_basePath === null) {
              $class = new \ReflectionClass($this);
              $this->_basePath = dirname($class->getFileName());
          }
  
          return $this->_basePath;
      }
docs: Returns the root directory of the module.
  It defaults to the directory containing the module class file.
  @return string the root directory of the module.