code: function iterable (data) {
      if (! haveSymbols) {
        // Fall back to `arrayLike` predicate in pre-ES6 environments.
        return arrayLike(data);
      }
  
      return assigned(data) && isFunction(data[Symbol.iterator]);
    }
docs: Public function `iterable`.
  
  Returns true if `data` is an iterable, false otherwise.