code: public SemanticVersion getNextParentVersion() {
      int major = head.getMajorVersion();
      int minor = head.getMinorVersion();
      int patch = head.getPatchVersion();
  
      switch (significantDigits) {
        case 1:
          throw new UnsupportedOperationException();
        case 2:
          major++;
          minor = 0;
          patch = 0;
          return new SemanticVersion(major, minor, patch);
        case 3:
          minor++;
          patch = 0;
          return new SemanticVersion(major, minor, patch);
        default:
          throw new UnsupportedOperationException();
      }
    }
docs: Strip the lowest number and increment the next one up. For example:
  
  1.2.3 becomes 1.3.0