T3Tangent.stack_frame
=====================

.. py:method:: t3toolbox.manifold.T3Tangent.stack_frame(tree)
   :staticmethod:


   .. code-block:: python

      def stack_frame(tree) -> 'T3Tangent':


   Stack a ``C``-shaped tree of single-base-point tangents into a frame-stacked T3Tangent.

   Inverse of :py:meth:`unstack_frame`. The leaves sit at **different** base points (distinct
   bases), so no shared-frame identity is required; they must share the same structure and the
   same tangent stack ``K``. The bases are stacked over the frame stack ``C``, which is placed
   innermost so the variation stack becomes ``K + C``.