function getExtensionFromUri(uri) {
  //>>includeStart('debug', pragmas.debug);
  if (!defined(uri)) {
    throw new DeveloperError("uri is required.");
  }
  //>>includeEnd('debug');

  const uriObject = new Uri(uri);
  uriObject.normalize();
  let path = uriObject.path();
  let index = path.lastIndexOf("/");
  if (index !== -1) {
    path = path.substr(index + 1);
  }
  index = path.lastIndexOf(".");
  if (index === -1) {
    path = "";
  } else {
    path = path.substr(index + 1);
  }
  return path;
}
Given a URI, returns the extension of the URI.
@function getExtensionFromUri

@param {string} uri The Uri.
@returns {string} The extension of the Uri.

@example
//extension will be "czml";
const extension = Cesium.getExtensionFromUri('/Gallery/simple.czml?value=true&example=false');