code: def hstack(tup):
      arrs = [atleast_1d(_m) for _m in tup]
      if arrs[0].ndim == 1:
          return concatenate(arrs, 0)
      return concatenate(arrs, 1)
  
imports: from __future__ import absolute_import
  import types
  import warnings
  from autograd.extend import primitive, notrace_primitive
  import numpy
  import autograd.builtins
  from numpy.core.einsumfunc import _parse_einsum_input
label_desc: Use image node_id 4 for calling a global function with example usage: hstack(tup) and returns: concatenate, concatenate