Node_Set::Clear() is not implemented

[pozdneev]

Compilation of file test.gm

Procedure test(G: Graph, s: Node_Set(G)) {
        s.Clear();
}

gives

test.gm:In procedure test:
test.gm:2: 43: error: Invalid built-in:Clear

File ./src/inc/gm_builtin.h does not have GM_BLTIN_SET_CLEAR item.

Thus, I conclude that Node_Set::Clear() is not implemented.
But documentation says, that Node_Set::Clear() exists (4.5.1 Built-in Operations Collection Types).