public static void main(String[] args) {
   // Testing string to integer
   System.out.println(String2Integer.string2Integer("213434"));
   System.out.println(String2Integer.string2Integer("-43645"));
   System.out.println(
       String2Integer.string2Integer(
           "9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999"));
 }
 public static void main(String[] args) {
   String2Integer str2int = new String2Integer();
   System.out.print(str2int.atoi("1 a"));
 }