code: public function getVendorPath()
      {
          if ($this->_vendorPath === null) {
              $this->setVendorPath($this->getBasePath() . DIRECTORY_SEPARATOR . 'vendor');
          }
  
          return $this->_vendorPath;
      }
docs: Returns the directory that stores vendor files.
  @return string the directory that stores vendor files.
  Defaults to "vendor" directory under [[basePath]].