_filters[$search][$replace])) { if (!isset($this->_filters[$search])) { $this->_filters[$search] = array(); } if (!isset($this->_filters[$search][$replace])) { $this->_filters[$search][$replace] = array(); } $this->_filters[$search][$replace] = new Swift_StreamFilters_StringReplacementFilter($search, $replace); } return $this->_filters[$search][$replace]; } }