code: function merge(target, source) {
                  target.additionalNodes = target.additionalNodes || [];
                  target.additionalNodes.push(source.node);
                  if (source.additionalNodes) {
                      (_a = target.additionalNodes).push.apply(_a, source.additionalNodes);
                  }
                  target.children = ts.concatenate(target.children, source.children);
                  if (target.children) {
                      mergeChildren(target.children);
                      sortChildren(target.children);
                  }
                  var _a;
              }
docs: Merge source into target. Source should be thrown away after this is called.