Что с форматером? Помогите понять, очень любопытно

import java.util.HashMap;
import java.util.Map;

public class Solution {
    public static Map<String, String> countries = new HashMap<String, String>();

    static {
        countries.put("UA", "Ukraine");
        countries.put("RU", "Russia");
        countries.put("CA", "Canada");
    }

    public static void main(String[] args) {
    }

    public static class IncomeDataAdapter implements Customer, Contact  {
        private IncomeData data;

        public IncomeDataAdapter(IncomeData data) {
            this.data = data;
        }

        public String getCompanyName() {
           return data.getCompany();
        }

        public String getCountryName() {
           return countries.get(data.getCountryCode());
        }
        public String getName() {
          return data.getContactLastName() + ", " + data.getContactFirstName();
        }

        public String getPhoneNumber() {
          String number = Integer.toString(data.getPhoneNumber());
         while (number.length() != 10) {
            number = "0" + number;
        }
          String[] array = number.split("");
          return String.format("+%d(%s%s%s)%s%s%s-%s%s-%s%s", getCountryPhoneCode() , array[0], array[1], array[2],
          array[3], array[4], array[5], array[6], array[7], array[8], array[9]);
    }
   }
  public static interface IncomeData {
        String getCountryCode();      //For example: UA

        String getCompany();            //For example: JavaRush Ltd.

        String getContactFirstName();   //For example: Ivan

        String getContactLastName();    //For example: Ivanov

        int getCountryPhoneCode();      //For example: 38

        int getPhoneNumber();           //For example: 501234567
    }

    public static interface Customer {
        String getCompanyName();        //For example: JavaRush Ltd.

        String getCountryName();        //For example: Ukraine
    }

    public static interface Contact {
        String getName();               //For example: Ivanov, Ivan

        String getPhoneNumber();        //For example: +38(050)123-45-67
    }
}