Function assertArg

test/angular/1.5/angular.js:1941–1946

* throw error if the argument is falsy.

(arg, name, reason)

 * throw error if the argument is falsy.
 */
function assertArg(arg, name, reason) {
  if (!arg) {
    throw ngMinErr('areq', 'Argument \'{0}\' is {1}', (name || '?'), (reason || 'required'));
  }
  return arg;
}

function assertArgFn(arg, name, acceptArrayAnnotation) {
  if (acceptArrayAnnotation && isArray(arg)) {