code: def test_is_fancy():
      slices = (2, [2], [2, 3], Ellipsis, np.array((2, 3)))
      for slice0 in slices:
          _check_slice(slice0)
          _check_slice((slice0,))  # tuple is same
          # Double ellipsis illegal in np 1.12dev - set up check for that case
          maybe_bad = slice0 is Ellipsis
          for slice1 in slices:
              if maybe_bad and slice1 is Ellipsis:
                  continue
              _check_slice((slice0, slice1))
      assert not is_fancy((None,))
      assert not is_fancy((None, 1))
      assert not is_fancy((1, None))
      # Check that actual False returned (rather than falsey)
      assert is_fancy(1) is False
  
imports: import time
  from functools import partial
  from io import BytesIO
  from itertools import product
  from threading import Lock, Thread
  import numpy
  import pytest
  from numpy.testing import assert_array_equal
  from ..fileslice import _positive_slice, _simple_fileslice, calc_slicedefs, canonical_slicers, fileslice, fill_slicer, is_fancy, optimize_read_slicers, optimize_slicer, predict_shape, read_segments, slice2len, slice2outax, slicers2segments, strided_scalar, threshold_heuristic
label_desc: Use image node_id 2 for calling a global function with example usage: test_is_fancy() without return types