// Optional: Set additional criteria for filtering estimates.
// See http://code.google.com/apis/adwords/docs/appendix/countrycodes.html
// for a detailed list of country codes.
// Set targeting criteria. Only locations and languages are supported.
$unitedStates = new Location();
$unitedStates->setId(2840);
// See http://code.google.com/apis/adwords/docs/appendix/languagecodes.html
// for a detailed list of language codes.
$english = new Language();
$english->setId(1000);
$campaignEstimateRequest->setCriteria([$unitedStates, $english]);