def METHOD_NAME(self):
    head_name = self.get_head_name()
    new_children = []
    for child in self.children:
        if child.get_head_name() == head_name and not child.parenthesised:
            new_children.extend(child.children)
        else:
            new_children.append(child)
    self.children = new_children
    return self