class_docstr: Tangent bundle of a space.
class_docstr_tok: ["Tangent","bundle","of","a","space","."]
code: def _stack(self, space_point, space_tangent_vec):
      return gs.stack(
          [space_point, space_tangent_vec], axis=-self.point_ndim
      )
  
imports: from joblib import Parallel, delayed
  import geomstats.backend
  from geomstats.geometry.base import Manifold
  from geomstats.geometry.riemannian_metric import RiemannianMetric
  from geomstats.vectorization import check_is_batch
label_desc: Use image node_id 4 for calling the TangentBundle obj's underlying member method code with example usage: obj._stack(space_point, space_tangent_vec) and returns: gs