class_docstr: Test AssertFunction layer.
class_docstr_tok: ["Test","AssertFunction","layer","."]
code: def test_reduce_rank_explicit_pass(self):
      layer = tl.AssertFunction(
          "xyzab->xyzc", tl.Flatten(n_axes_to_keep=3)
      )
      x = np.ones((1, 2, 3, 4, 5))
      layer(x)
  
imports: from absl.testing import absltest
  import numpy
  import trax.layers
label_desc: Use image node_id 4 for calling the AssertFunctionTest obj's underlying member method code with example usage: obj.test_reduce_rank_explicit_pass() without return types