code: public static void main(String[] args) {
  
  		String[] input = { "check_ins", "CheckIns", "blog_entry", "BlogEntry", "blog_entries", "BlogEntries", "blogentry", "blogentries" };
  
  		for (int i = 0; i < input.length; i++) {
  
  			System.out.println(StringUtils.rightPad(input[i], 20) + StringUtils.leftPad(toUpperCamelCase(input[i]), 20) + StringUtils.leftPad(toUnderscore(input[i], true), 20)
  					   + StringUtils.leftPad(toUnderscore(input[i], false), 20));
  
  		}
  	}
docs: Test method.