docs: @Nonnull
      public InstallState getInstallState() {
          if (installState != null) {
              installStateName = installState.name();
              installState = null;
          }
          InstallState is = installStateName != null ? InstallState.valueOf(installStateName) : InstallState.UNKNOWN;
          return is != null ? is : InstallState.UNKNOWN;
      }