old_contents: from plugins.trezor.qt_generic import QtPlugin
  from keepkeylib.qt.pinmatrix import PinMatrixWidget
  
  class Plugin(QtPlugin):
      handler_class = KeepKeyQtHandler
      icon_file = ":icons/keepkey.png"
  
new_contents: from plugins.trezor.qt_generic import QtPlugin
  from keepkeylib.qt.pinmatrix import PinMatrixWidget
  
  class Plugin(QtPlugin):
      pin_matrix_widget_class = PinMatrixWidget
      icon_file = ":icons/keepkey.png"
  
subject: Update as for trezor/qt.py