code: public static <T1, T2, T3> TriFunction<T1, T2, T3, Boolean> function(TriPredicate<T1, T2, T3> adaptee) {
          dbc.precondition(adaptee != null, "cannot adapt a null predicate");
          return adaptee::test;
      }
docs: Adapts a ternary predicate to a ternary function.
  
  @param <T1> the predicate first parameter type
  @param <T2> the predicate second parameter type
  @param <T3> the predicate third parameter type
  @param adaptee the predicate to be adapted
  @return the adapted function