code: def create_combobox(self, text, choices, option, default=NoDefault,
                          tip=None, restart=False):
          
          label = QLabel(text)
          combobox = QComboBox()
          if tip is not None:
              combobox.setToolTip(tip)
          for name, key in choices:
              if not (name is None and key is None):
                  combobox.addItem(name, to_qvariant(key))
          # Insert separators
          count = 0
          for index, item in enumerate(choices):
              name, key = item
              if name is None and key is None:
                  combobox.insertSeparator(index + count)
                  count += 1
          self.comboboxes[combobox] = (option, default)
          layout = QHBoxLayout()
          layout.addWidget(label)
          layout.addWidget(combobox)
          layout.addStretch(1)
          layout.setContentsMargins(0, 0, 0, 0)
          widget = QWidget(self)
          widget.label = label
          widget.combobox = combobox
          widget.setLayout(layout)
          combobox.restart_required = restart
          combobox.label_text = text
          return widget
docs: choices: couples (name, key)