class_docstr: Wraps a :class:`GroupParameterItem` to manage ``bool`` parameter children. Also provides convenience buttons to
  select or clear all values at once. Note these conveniences are disabled when ``exclusive`` is *True*.
code: def expandedChangedEvent(self, expanded):
      for btn in self.metaBtns.values():
          btn.setVisible(expanded)
  
imports: from ...None import functions
  from ...Qt import QtWidgets
  from ...SignalProxy import SignalProxy
  from ..ParameterItem import ParameterItem
  from .None import BoolParameterItem, SimpleParameter
  from .basetypes import Emitter, GroupParameter, GroupParameterItem, WidgetParameterItem
  from .list import ListParameter
label_desc: Use image node_id 10 for calling the ChecklistParameterItem obj's underlying member method code with example usage: obj.expandedChangedEvent(expanded) without return types