next_values

        # Enumerator.next_values

(from ruby core)
---
    e.next_values   -> array

---

Returns the next object as an array in the enumerator, and move the
internal position forward.  When the position reached at the end,
StopIteration is raised.

See class-level notes about external iterators.

This method can be used to distinguish `yield` and `yield nil`.

### Example

    o = Object.new
    def o.each
      yield
      yield 1
      yield 1, 2
      yield nil
      yield [1, 2]
    end
    e = o.to_enum
    p e.next_values
    p e.next_values
    p e.next_values
    p e.next_values
    p e.next_values
    e = o.to_enum
    p e.next
    p e.next
    p e.next
    p e.next
    p e.next

    ## yield args       next_values      next
    #  yield            []               nil
    #  yield 1          [1]              1
    #  yield 1, 2       [1, 2]           [1, 2]
    #  yield nil        [nil]            nil
    #  yield [1, 2]     [[1, 2]]         [1, 2]