code: func (it *Int64) Contains(ctx context.Context, tsv graph.Value) bool {
  	graph.ContainsLogIn(it, tsv)
  	it.runstats.Contains += 1
  	v := valToInt64(tsv)
  	if it.min <= v && v <= it.max {
  		it.result = v
  		return graph.ContainsLogOut(it, it.toValue(v), true)
  	}
  	return graph.ContainsLogOut(it, it.toValue(v), false)
  }
docs: // Contains() for an Int64 is merely seeing if the passed value is
  // within the range, assuming the value is an int64.