combine3<T1 extends Object, T2 extends Object, T3 extends Object>  static method 
Combines 3 Option outcomes into 1 containing a tuple of their values if all are Some.
See also: combineOption.
Implementation
static Option<(T1, T2, T3)>
combine3<T1 extends Object, T2 extends Object, T3 extends Object>(
  Option<T1> o1,
  Option<T2> o2,
  Option<T3> o3, //,
) {
  return combineOption<Object>([
    o1,
    o2,
    o3,
  ]).map((l) => (l[0] as T1, l[1] as T2, l[2] as T3));
}