code: def loaded_api():
      """Return which API is loaded, if any
  
      If this returns anything besides None,
      importing any other Qt binding is unsafe.
  
      Returns
      -------
      None, 'pyside2', 'pyside', 'pyqt', 'pyqt5', or 'pyqtv1'
      """
      if "PyQt4.QtCore" in sys.modules:
          if qtapi_version() == 2:
              return QT_API_PYQT
          else:
              return QT_API_PYQTv1
      elif "PySide.QtCore" in sys.modules:
          return QT_API_PYSIDE
      elif "PySide2.QtCore" in sys.modules:
          return QT_API_PYSIDE2
      elif "PyQt5.QtCore" in sys.modules:
          return QT_API_PYQT5
      return None
  
imports: import sys
  import types
  from functools import partial
  from IPython.utils.version import check_version
label_desc: Use image node_id 2 for calling a global function with example usage: loaded_api() and returns: None, QT_API_PYQT, QT_API_PYQTv1, QT_API_PYSIDE, QT_API_PYSIDE2, QT_API_PYQT5