class_docstr: Test that the QASM serialization works correctly
  when circuits are created via QNodes.
class_docstr_tok: ["Test","that","the","QASM","serialization","works","correctly","when","circuits","are","created","via","QNodes","."]
docstr: Test that an empty QNode is properly
  serialized into an empty QASM program.
docstr_tok: ["Test","that","an","empty","QNode","is","properly","serialized","into","an","empty","QASM","program","."]
code: def test_empty_circuit(self):
      """Test that an empty QNode is properly
      serialized into an empty QASM program."""
      dev = qml.device("default.qubit", wires=1)
  
      @qml.qnode(dev)
      def qnode():
          return qml.expval(qml.PauliZ(0))
  
      # construct the qnode circuit
      qnode()
  
      res = qnode.qtape.to_openqasm()
      expected = dedent(
          """\
              OPENQASM 2.0;
              include "qelib1.inc";
              qreg q[1];
              creg c[1];
              measure q[0] -> c[0];
              """
      )
      assert res == expected
  
imports: from textwrap import dedent
  import numpy
  import pytest
  import pennylane
  from pennylane.wires import Wires
label_desc: Use image node_id 1 for calling the TestQNodeQasmIntegrationTests obj's underlying member method code with example usage: obj.test_empty_circuit() and returns: qml