private com.google.protobuf.SingleFieldBuilderV3<
              com.google.cloud.vertexai.api.GenerationConfig.RoutingConfig.ManualRoutingMode,
              com.google.cloud.vertexai.api.GenerationConfig.RoutingConfig.ManualRoutingMode
                  .Builder,
              com.google.cloud.vertexai.api.GenerationConfig.RoutingConfig
                  .ManualRoutingModeOrBuilder>
          getManualModeFieldBuilder() {
        if (manualModeBuilder_ == null) {
          if (!(routingConfigCase_ == 2)) {
            routingConfig_ =
                com.google.cloud.vertexai.api.GenerationConfig.RoutingConfig.ManualRoutingMode
                    .getDefaultInstance();
          }
          manualModeBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.cloud.vertexai.api.GenerationConfig.RoutingConfig.ManualRoutingMode,
                  com.google.cloud.vertexai.api.GenerationConfig.RoutingConfig.ManualRoutingMode
                      .Builder,
                  com.google.cloud.vertexai.api.GenerationConfig.RoutingConfig
                      .ManualRoutingModeOrBuilder>(
                  (com.google.cloud.vertexai.api.GenerationConfig.RoutingConfig.ManualRoutingMode)
                      routingConfig_,
                  getParentForChildren(),
                  isClean());
          routingConfig_ = null;
        }
        routingConfigCase_ = 2;
        onChanged();
        return manualModeBuilder_;
      }
<pre>
Manual routing.
</pre>

<code>
.google.cloud.vertexai.v1.GenerationConfig.RoutingConfig.ManualRoutingMode manual_mode = 2;
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/GenerationConfig.java