class_docstr: Test that wire lines are produced correctly in different situations.
class_docstr_tok: ["Test","that","wire","lines","are","produced","correctly","in","different","situations","."]
docstr: Test a single layer with multiple wires. Check that the expected number
  of wires are drawn, and they are in the correct location.
code: def test_single_layer(self):
      """Test a single layer with multiple wires. Check that the expected number
      of wires are drawn, and they are in the correct location."""
  
      with qml.queuing.AnnotatedQueue() as q_tape:
          qml.PauliX(0)
          qml.PauliY(1)
          qml.PauliZ(2)
  
      tape = QuantumScript.from_queue(q_tape)
      _, ax = tape_mpl(tape)
  
      assert len(ax.lines) == 3
      for wire, line in enumerate(ax.lines):
          assert line.get_xdata() == (
              -1,
              1,
          )  # from -1 to number of layers
          assert line.get_ydata() == (wire, wire)
  
      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 TestWires obj's underlying member method code with example usage: obj.test_single_layer() without return types