docs: private static String capitalise(String s) {
      if(s.length()==0){return s;}
  
    StringBuilder s1=new StringBuilder(s);
    if (Character.isLowerCase(s1.charAt(0))){
      s1.setCharAt(0,Character.toUpperCase(s1.charAt(0)));
    }	
    for(int j=1;j<s1.length();j++){
      if(Character.isUpperCase(s1.charAt(j))){
        s1.setCharAt(j,Character.toLowerCase(s1.charAt(j)));
      }
    }
    return s1.toString();
    }