public Range<C> to(C to){
  Objects.requireNonNull(to);
  this.to=to;
  toIncluded=true;
  return this;
}

public Range < C > to ( C to ) { Objects . requireNonNull ( to ) ; this . to = to ; toIncluded = true ; return this ; }
set end point . the end point is included in this range .
