code: def test_lsh_ff(self):
      with fastmath.use_backend(fastmath.Backend.JAX):
          layer = efficient_attention.LSHFF(
              d_ff=1024 * 8, n_buckets=[16, 8]
          )
          x = np.ones((3, 7, 1024)).astype(np.float32)
          _, _ = layer.init(shapes.signature(x))
          y = layer(x)
          self.assertEqual(y.shape, x.shape)
  
imports: from absl.testing import parameterized
  import jax
  import numpy
  from tensorflow import test
  from trax import fastmath
  from trax import shapes
  from trax.fastmath import numpy
  from trax.layers.research import efficient_attention
label_desc: Use image node_id 2 for calling the EfficientAttentionTest obj's underlying member method code with example usage: obj.test_lsh_ff() without return types