src/Baum/SetValidator.php
protected function validateRootsByScope($roots) {
    foreach($this->groupRootsByScope($roots) as $scope => $groupedRoots) {
      $valid = $this->isEachRootValid($groupedRoots);

      if ( !$valid )
        return false;
    }

    return true;
  }
protected function validateRootsByScope($roots) {
    foreach($this->groupRootsByScope($roots) as $scope => $groupedRoots) {
      $valid = $this->isEachRootValid($groupedRoots);

      if ( !$valid )
        return false;
    }

    return true;
  }
Check that each root node in the list supplied satisfies that its bounds
values (lft, rgt indexes) are less than the next *within each scope*.

@param   mixed   $roots
@return  boolean