code: public static boolean commonSuffixOfLength(String s, String p, int len) {
          return s != null && p != null && len >= 0 && s.regionMatches(s.length() - len, p, p.length() - len, len);
      }
docs: Checks if two strings have the same suffix of specified length
  
  @param s   string
  @param p   string
  @param len length of the common suffix
  @return true if both s and p are not null and both have the same suffix. Otherwise - false