private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.visionai.v1.PacketType,
            com.google.cloud.visionai.v1.PacketType.Builder,
            com.google.cloud.visionai.v1.PacketTypeOrBuilder>
        getTypeFieldBuilder() {
      if (typeBuilder_ == null) {
        typeBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.visionai.v1.PacketType,
                com.google.cloud.visionai.v1.PacketType.Builder,
                com.google.cloud.visionai.v1.PacketTypeOrBuilder>(
                getType(), getParentForChildren(), isClean());
        type_ = null;
      }
      return typeBuilder_;
    }
<pre>
Input only. Immutable. The type of the payload.
</pre>

<code>
.google.cloud.visionai.v1.PacketType type = 2 [(.google.api.field_behavior) = INPUT_ONLY, (.google.api.field_behavior) = IMMUTABLE];
</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/PacketHeader.java