docstr: Test the flatten and unflatten methods of identity.
docstr_tok: ["Test","the","flatten","and","unflatten","methods","of","identity","."]
code: def test_flatten_unflatten(self, wires):
      """Test the flatten and unflatten methods of identity."""
      op = Identity(wires)
      data, metadata = op._flatten()
      assert data == tuple()
      assert metadata[0] == qml.wires.Wires(wires)
      assert metadata[1] == tuple()
  
      new_op = Identity._unflatten(*op._flatten())
      assert qml.equal(op, new_op)
  
file_path: pennylane/tests/ops/test_identity.py
imports: import numpy
  import pytest
  import pennylane
  from pennylane import Identity
label_desc: Use image node_id 1 for calling the TestIdentity obj's underlying member method code with example usage: obj.test_flatten_unflatten(wires) without return types