code: def _triu_inverse(x):
      if x.dim() == 1:
          return x.reciprocal()
      else:
          identity = torch.eye(
              x.size(-1), dtype=x.dtype, device=x.device
          )
          return torch.linalg.solve_triangular(x, identity, upper=True)
  
imports: import math
  from collections import namedtuple
  import torch
  import pyro
  from pyro.ops.arrowhead import SymmArrowhead, sqrt, triu_gram, triu_inverse, triu_matvecmul
  from pyro.ops.dual_averaging import DualAveraging
  from pyro.ops.welford import WelfordArrowheadCovariance, WelfordCovariance
label_desc: Use image node_id 4 for calling a global function with example usage: _triu_inverse(x) and returns: x, torch