Function assertInstanceof

deps/v8/test/intl/assert.js:199–210

* Throws if obj is not of given type.

(obj, type)

 * Throws if obj is not of given type.
 */
function assertInstanceof(obj, type) {
  if (!(obj instanceof type)) {
    var actualTypeName = null;
    var actualConstructor = Object.getPrototypeOf(obj).constructor;
    if (typeof actualConstructor == "function") {
      actualTypeName = actualConstructor.name || String(actualConstructor);
    }
    throw new Error('Object <' + obj + '> is not an instance of <' +
                    (type.name || type) + '>' +
                    (actualTypeName ? ' but of < ' + actualTypeName + '>' : ''));
  }
}

/**
 * Split a BCP 47 language tag into locale and extension.