class_docstr: Tests operations are placed into layers correctly.
class_docstr_tok: ["Tests","operations","are","placed","into","layers","correctly","."]
docstr: Tests the positions when multiple gates are all on the same wire.
code: def test_three_layers_one_wire(self):
      """Tests the positions when multiple gates are all on the same wire."""
  
      with qml.queuing.AnnotatedQueue() as q_tape:
          qml.PauliX(0)
          qml.PauliX(0)
          qml.PauliX(0)
  
      tape = QuantumScript.from_queue(q_tape)
      _, ax = tape_mpl(tape)
  
      for layer, box in enumerate(ax.patches):
          assert box.get_x() == layer - self.width / 2.0
          assert box.get_y() == -self.width / 2.0
  
      for t in ax.texts[1:]:
          assert t.get_text() == "X"
      plt.close()
  
imports: import pytest
  import pennylane
  from pennylane.drawer import tape_mpl
  from pennylane.tape import QuantumScript
label_desc: Use image node_id 2 for calling the TestLayering obj's underlying member method code with example usage: obj.test_three_layers_one_wire() without return types