code: def tril_to_vec(x, k=0):
      n = x.shape[-1]
      rows, cols = _np.tril_indices(n, k=k)
      return x[..., rows, cols]
  
imports: from ._dispatch import BACKEND_NAME, _common
  from ._dispatch import numpy
label_desc: Use image node_id 19 for calling a global function with example usage: tril_to_vec(x, k) and returns: x