code: def test_multihead_mask_warning(self):
      rng = random.key(0)
      rng1, rng2 = random.split(rng, num=2)
  
      length = 10
      dim = 1
      num_heads = 1
      input_shape = (1, length, dim)
      query = key = random.normal(rng2, input_shape)
  
      module = nn.MultiHeadDotProductAttention(
          num_heads=num_heads,
          kernel_init=jax.nn.initializers.ones,
          deterministic=False,
      )
  
      initial_vars = module.init(rng1, query, key)
      causal_mask = nn.attention.make_causal_mask(
          jnp.ones(input_shape[:-1])
      )
  
      module.apply(initial_vars, query, key, mask=causal_mask)
      with self.assertWarnsRegex(
          DeprecationWarning,
          "the function signature of MultiHeadDotProductAttention's `__call__` method has changed",
      ):
          with self.assertRaises(errors.ScopeParamShapeError):
              module.apply(initial_vars, query, key, causal_mask)
  
imports: import jax
  import jax.numpy
  import numpy
  from absl.testing import absltest, parameterized
  from jax import lax, random
  from jax.nn import initializers
  from flax import errors, jax_utils
  from flax import linen
  from flax.core import pop
label_desc: Use image node_id 11 for calling the AttentionTest obj's underlying member method code with example usage: obj.test_multihead_mask_warning() without return types