code: public static <T> Ix<T> repeatValue(T value, long count) {
          return new IxRepeatCount<T>(value, nonNegative(count, "count"));
      }
docs: Repeats the given value at most count times.
  <p>
  A count of zero will yield an empty sequence, a count of one
  will yield a sequence with only one element and so forth.
  <p>
  The result's iterator() doesn't support remove().
  @param <T> the value type
  @param value the value to emit
  @param count the number of times to emit the value, non-negative
  @return the new Ix instance
  @throws IllegalArgumentException if count is negative
  @since 1.0