code: public static AndroidPublisher init( String applicationName, String serviceAccountEmail, File pk12File )
              throws IOException, GeneralSecurityException
      {
  
          // Authorization.
          newTrustedTransport();
          Credential credential = authorizeWithServiceAccount( serviceAccountEmail, pk12File );
  
          // Set up and return API client.
          return new AndroidPublisher.Builder( httpTransport, JSON_FACTORY, credential )
                  .setApplicationName( applicationName )
                  .build();
      }
docs: Performs all necessary setup steps for running requests against the API.
  
  @param serviceAccountEmail the Service Account Email (empty if using
  installed application)
  @return the {@Link AndroidPublisher} service
  @throws GeneralSecurityException
  @throws IOException