old_contents: from __future__ import absolute_import
  
  import pytest
  from qtpy import PYQT5, PYSIDE2, QtCore
  
  """Test QtCore."""
  
  
  def test_qtmsghandler():
      """Test qtpy.QtMsgHandler"""
      assert QtCore.qInstallMessageHandler is not None
  
  
  @pytest.mark.skipif(not (PYQT5 or PYSIDE2),
                      reason="Targeted to PyQt5 or PySide2")
  def test_DateTime_toPython():
      """Test QDateTime.toPython"""
      assert QtCore.QDateTime.toPython is not None
  
new_contents: from __future__ import absolute_import
  
  import pytest
  from qtpy import PYQT5, PYSIDE2, QtCore
  
  """Test QtCore."""
  
  
  def test_qtmsghandler():
      """Test qtpy.QtMsgHandler"""
      assert QtCore.qInstallMessageHandler is not None
  
  
  @pytest.mark.skipif(not (PYQT5 or PYSIDE2),
                      reason="Targeted to PyQt5 or PySide2")
  def test_DateTime_toPython():
      """Test QDateTime.toPython"""
      assert QtCore.QDateTime.toPython is not None
  
  
  def test_QtCore_SignalInstance():
      class ClassWithSignal(QtCore.QObject):
          signal = QtCore.Signal()
  
      instance = ClassWithSignal()
  
      assert isinstance(instance.signal, QtCore.SignalInstance)
  
subject: add test for QtCore.SignalInstance