src/main/java/js/http/captcha/Challenge.java
public boolean verifyResponse(String token) throws NullPointerException {
		return value.equals(getValue(tokenedImageFiles.get(token)));
	}
public boolean verifyResponse(String token) throws NullPointerException {
		return value.equals(getValue(tokenedImageFiles.get(token)));
	}
Test that selected image identified by given token is the right response.

@param token unique token identifying selected image, null or empty tolerated.
@return true if token identifies this challenge response.