code: def test_self_attention(self):
      with fastmath.use_backend(fastmath.Backend.JAX):
          layer = efficient_attention.SelfAttention(
              n_heads=5,
              d_qk=7,
              d_v=17,
              share_qk=False,
              causal=True,
              chunk_len=8,
              n_chunks_before=1,
              n_chunks_after=0,
              use_reference_code=True,
              attention_dropout=0.0,
              mode="train",
          )
          x = np.ones((3, 32, 8)).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 1 for calling the EfficientAttentionTest obj's underlying member method code with example usage: obj.test_self_attention() without return types