code: def test_callable():
      c = ct.EnsureCallable()
      # this should always work
      assert_equal(c(range), range)
      assert_raises(ValueError, c, "range")
  
file_path: datalad/datalad/tests/test_constraints.py
imports: from datalad.tests.utils_pytest import assert_equal, assert_raises
  from ..support import constraints
label_desc: Use image node_id 7 for calling a global function with example usage: test_callable() without return types