code: private void validateConfiguration(SessionConfiguration configuration) {
          String nullError = "%s must not be null";
          String sampleError = "Please update your %s in the gradle.properties of the project before " +
                  "using the Uber SDK Sample app. For a more secure storage location, " +
                  "please investigate storing in your user home gradle.properties ";
  
          checkNotNull(configuration, String.format(nullError, "SessionConfiguration"));
          checkNotNull(configuration.getClientId(), String.format(nullError, "Client ID"));
          checkNotNull(configuration.getRedirectUri(), String.format(nullError, "Redirect URI"));
          checkState(!configuration.getClientId().equals("insert_your_client_id_here"),
                  String.format(sampleError, "Client ID"));
          checkState(!configuration.getRedirectUri().equals("insert_your_redirect_uri_here"),
                  String.format(sampleError, "Redirect URI"));
      }
docs: Validates the local variables needed by the Uber SDK used in the sample project
  @param configuration