code: private function cascade()
      {
          if ($this->hierarchy) { // if there is a hierarchy defined
              foreach ($this->hierarchy as $key => $value) { // loop through each hierarchy
                  $file = $this->page . '-' . $value;
                  if ($this->fileExists($file)) { // if that file exists then return it
                      $this->hierarchy = array(); // reset hierarchy for further renders
                      return $file;
                  }
              }
              $this->hierarchy = array(); // reset hierarchy for further renders
          }
          return $this->page; // if no page found then return base page
      }
docs: /*
  Private: Cascade through template hierarchy
  
  Returns matched page