code: function addTypesToUnion(typeSet, types) {
              for (var _i = 0, types_4 = types; _i < types_4.length; _i++) {
                  var type = types_4[_i];
                  addTypeToUnion(typeSet, type);
              }
          }
docs: Add the given types to the given type set. Order is preserved, duplicates are removed, and nested types of the given kind are flattened into the set.