class_docstr: Tests for the cwire_connections helper method.
class_docstr_tok: ["Tests","for","the","cwire_connections","helper","method","."]
docstr: Test null behavior with an empty circuit.
docstr_tok: ["Test","null","behavior","with","an","empty","circuit","."]
code: def test_null_circuit(self):
      """Test null behavior with an empty circuit."""
      layers, wires = cwire_connections([[]], {})
      assert layers == []
      assert wires == []
  
imports: import pytest
  import pennylane
  from pennylane.drawer.utils import default_wire_map, default_bit_map, convert_wire_order, unwrap_controls, cwire_connections
  from pennylane.wires import Wires
label_desc: Use image node_id 1 for calling the TestCwireConnections obj's underlying member method code with example usage: obj.test_null_circuit() without return types