private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.visionai.v1.PacketHeader,
            com.google.cloud.visionai.v1.PacketHeader.Builder,
            com.google.cloud.visionai.v1.PacketHeaderOrBuilder>
        getHeaderFieldBuilder() {
      if (headerBuilder_ == null) {
        headerBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.visionai.v1.PacketHeader,
                com.google.cloud.visionai.v1.PacketHeader.Builder,
                com.google.cloud.visionai.v1.PacketHeaderOrBuilder>(
                getHeader(), getParentForChildren(), isClean());
        header_ = null;
      }
      return headerBuilder_;
    }
<pre>
The packet header.
</pre>

<code>.google.cloud.visionai.v1.PacketHeader header = 1;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/Packet.java