tv_stack_frame_stack
====================

.. py:function:: t3toolbox.backend.tv_operations.tv_stack_frame_stack(paired_tree)

   .. code-block:: python

      def tv_stack_frame_stack(
              paired_tree,  # array-like tree (shape G) of (frame_data, variations_data) pairs
      ):  # -> (
          #        frame-data,       # stack = G
          #        variations-data,  # stack = V + G
          #    )


   Stack a G-shaped tree of ``(frame_data, variations_data)`` pairs over the frame stack G.

   The frame stack is placed *innermost* (the variation stack becomes V + G), matching the base-inner
   convention. Takes exactly the paired-tree layout that :py:func:`tv_unstack_frame_stack` produces (its
   inverse), so a backend user round-trips without splitting the pairs by hand.