@java.lang.Override
  public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
    if (((bitField0_ & 0x00000001) != 0)) {
      output.writeMessage(1, getCreateTime());
    }
    if (((bitField0_ & 0x00000002) != 0)) {
      output.writeMessage(2, getEndTime());
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(target_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 3, target_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(verb_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 4, verb_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(statusMessage_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 5, statusMessage_);
    }
    if (requestedCancellation_ != false) {
      output.writeBool(6, requestedCancellation_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(apiVersion_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 7, apiVersion_);
    }
    getUnknownFields().writeTo(output);
  }
<pre>
Output only. API version used to start the operation.
</pre>

<code>string api_version = 7 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>

@return The bytes for apiVersion.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/OperationMetadata.java