/**
  * Returns a child object, by its name.
  *
  * @param string $name
  * @throws DAV\Exception\NotFound
  * @return IPrincipal
  */
 public function getChild($name)
 {
     $principalInfo = $this->principalBackend->getPrincipalByPath($this->principalPrefix . '/' . $name);
     if (!$principalInfo) {
         throw new DAV\Exception\NotFound('Principal with name ' . $name . ' not found');
     }
     return $this->getChildForPrincipal($principalInfo);
 }