code: function _pruneOrOrphan(p) {
              if (!_isInsideParent(p.el, p.pos)) {
                  p.el._jsPlumbGroup.remove(p.el);
                  if (prune) {
                      _jsPlumb.remove(p.el);
                  } else {
                      _orphan(p.el);
                  }
              }
          }
docs: remove an element from the group, then either prune it from the jsplumb instance, or just orphan it.