code: def test_sparse_ff_predict_equals_eval(self):
      with fastmath.use_backend(fastmath.Backend.JAX):
          d_model = 64
          seq_len = 6
          x_shape = (1, seq_len, d_model)
          inp = np.ones(x_shape).astype(np.float32)
  
          model_fn = functools.partial(
              sparsity.SparseFF,
              d_ff=256,
              temperature=0.7,
              n_elements_in_block=8,
          )
  
          configs = [
              {"multiply_by_controller_output": True},
              {"multiply_by_controller_output": False},
              {"ff_chunk_size": 2},
          ]
  
          test_utils.test_eval_equals_predict_configs(
              inp, model_fn, configs
          )
  
imports: import functools
  from absl.testing import parameterized
  import jax
  import numpy
  from tensorflow import test
  from trax import fastmath
  from trax import shapes
  import trax.layers
  from trax.layers import test_utils
  from trax.layers.research import sparsity
label_desc: Use image node_id 3 for calling the EfficientFeedForwardTest obj's underlying member method code with example usage: obj.test_sparse_ff_predict_equals_eval() without return types