code: @SafeVarargs
      public static <T> T firstNonNull(Supplier<T>... suppliers) {
          return firstNonNull(Supplier::get, suppliers);
      }
docs: Gets first supplier's result which is not null.
  Suppliers are called sequentially. Once a non-null result is obtained the remaining suppliers are not called.
  
  @param <T>       type of result returned by suppliers.
  @param suppliers all possible suppliers that might be able to supply a value.
  @return first result obtained which was not null, OR <code>null</code> if all suppliers returned <code>null</code>.