Function invokeArrayArg

docs/tests/v2/es6/js/sanddance.js:51365–51372

* if the argument is an array, we want to execute the fn on each entry * if it aint an array we don't want to do a thing. * this is used by all the methods that accept a single and array argument. * @param {*|Array} arg * @param {String} fn * @param {Object} [context] * @returns {B

(arg, fn, context)

  function invokeArrayArg(arg, fn, context) {
    if (Array.isArray(arg)) {
      each(arg, context[fn], context);
      return true;
    }

    return false;
  }
  /**
   * walk objects and arrays
   * @param {Object} obj