code: def _stack(values, axis=0, name="stack"):
      del name
      values = [ops.convert_to_tensor(x) for x in values]
      if values:
          return np.stack(values, axis=axis)
      else:
          if axis != 0:
              raise IndexError(f"Axis {axis} is out of range.")
          return np.zeros([0], np.float32)
  
imports: import functools
  import numpy
  import numpy
  from tensorflow_probability.python.internal.backend.numpy import _utils
  from tensorflow_probability.python.internal.backend.numpy import ops
  from tensorflow_probability.python.internal.backend.numpy.linalg_impl import einsum
  from tensorflow_probability.python.internal.backend.numpy.linalg_impl import norm
  from tensorflow_probability.python.internal.backend.numpy.linalg_impl import tensordot
label_desc: Use image node_id 19 for calling a global function with example usage: _stack(values, axis, name) and returns: np, np