code: public NegateMultiPos<S, Integer, Integer> setBetns(int leftIndex, int rightIndex) {
  		return new NegateMultiPos<S, Integer, Integer>(leftIndex, rightIndex) {
  
  			@Override protected S result() {
  				return delegateQueue('I', left, right, pos, position, null, plusminus, filltgt);
  			}
  		};
  	}
docs: Sets the substring in given left index and right index as the delegate string
  <p><b>The look result same as {@link StrMatcher#finder()}'s behavior</b>
  
  @see StrMatcher#finder()
  @param leftIndex
  @param rightIndex
  @return