_SetOwner
void _SetOwner(BWindow* newOwner);
item->_SetOwner(0);
item->_SetOwner(m_view);
item->_SetOwner(m_view);
void _SetOwner(DiagramView *owner);
virtual void _SetOwner(
item->_SetOwner(this);
item->_SetOwner(0);
child->_SetOwner(fOwner);
child->_SetOwner(newOwner);
_SetOwner(NULL);
fTopView->_SetOwner(this);