class_docstr: Class for an n-fold product manifold :math:`M^n`.
  
  Define a manifold as the product manifold of n copies of a given base
  manifold M.
  
  Parameters
  ----------
  base_manifold : Manifold
      Base manifold.
  n_copies : int
      Number of replication of the base manifold.
  default_coords_type : str, {\'intrinsic\', \'extrinsic\', etc}
      Coordinate type.
      Optional, default: 'intrinsic'.
docstr: Metric to equip the space with if equip is True.
docstr_tok: ["Metric","to","equip","the","space","with","if","equip","is","True","."]
code: def default_metric():
      """Metric to equip the space with if equip is True."""
      return NFoldMetric
  
imports: import geomstats.backend
  import geomstats.errors
  from geomstats.geometry.manifold import Manifold
  from geomstats.geometry.riemannian_metric import RiemannianMetric
  from geomstats.vectorization import get_batch_shape
label_desc: Use image node_id 2 for calling the NFoldManifold obj's underlying member method code with example usage: obj.default_metric() and returns: NFoldMetric