/**
  * Filter the query by a related \SpoilerWiki\Snippet object
  *
  * @param \SpoilerWiki\Snippet|ObjectCollection $snippet the related object to use as filter
  * @param string $comparison Operator to use for the column comparison, defaults to Criteria::EQUAL
  *
  * @return ChildMilestoneQuery The current query, for fluid interface
  */
 public function filterBySnippet($snippet, $comparison = null)
 {
     if ($snippet instanceof \SpoilerWiki\Snippet) {
         return $this->addUsingAlias(MilestoneTableMap::COL_ID, $snippet->getIntroducedAt(), $comparison);
     } elseif ($snippet instanceof ObjectCollection) {
         return $this->useSnippetQuery()->filterByPrimaryKeys($snippet->getPrimaryKeys())->endUse();
     } else {
         throw new PropelException('filterBySnippet() only accepts arguments of type \\SpoilerWiki\\Snippet or Collection');
     }
 }