code: def _new_instance(cls, children=None, connector=None, negated=False):
          
          obj = QBase(children, connector, negated)
          obj.__class__ = cls
          return obj
docs: Create a new instance of this class when new Nodes (or subclasses) are
          needed in the internal code in this class. Normally, it just shadows
          __init__(). However, subclasses with an __init__ signature that aren't
          an extension of Node.__init__ might need to implement this method to
          allow a Node to create a new instance of them (if they have any extra
          setting up to do).