code: def test_no_value():
      a = nn.Variable(())
      b = nn.Variable(())
      with pytest.raises(RuntimeError):
          F.concatenate(*[a, b], axis=0)
  
file_path: nnabla/python/test/function/test_concatenate.py
imports: import pytest
  import numpy
  import nnabla
  import nnabla.functions
  from nbla_test_utils import list_context
label_desc: Use image node_id 3 for calling a global function with example usage: test_no_value() without return types