static <A> A optPar(ThreadLocal<A> tl, A defaultValue) {
  A a = tl.get();
  if (a != null) {
    tl.set(null);
    ret a;
  }
  ret defaultValue;
}

static <A> A optPar(ThreadLocal<A> tl) {
  ret optPar(tl, null);
}

sO optPar(O[] params, S name) {
  ret optParam(params, name);
}

sO mapMethodLike optPar(S name, O[] params) {
  ret optParam(params, name);
}

sO mapMethodLike optPar(S name, Map params) {
  ret optParam(name, params);
}

static <A> A optPar(O[] params, S name, A defaultValue) {
  ret optParam(params, name, defaultValue);
}

static <A> A optPar(S name, O[] params, A defaultValue) {
  ret optParam(params, name, defaultValue);
}

Began life as a copy of #1006091