svoid tok_ifNullAssign(LS tok) {
  for (int i : jfindAll_reversed(tok, "return <id> if null =")) {
    S var = tok.get(i+2);
    int iEnd = findEndOfStatement(tok, i);
    tok.set(iEnd-1, "; return \*var*/; }");
    replaceTokens(tok, i, i+5*2-1,
      "{ if (\*var*/ == null) \*var*/ =");
  }
  
  jreplace(tok, "<id> if null =", "if ($1 == null) $1 =");
}