public Builder mergeType(com.google.cloud.visionai.v1.PacketType value) {
      if (typeBuilder_ == null) {
        if (((bitField0_ & 0x00000002) != 0)
            && type_ != null
            && type_ != com.google.cloud.visionai.v1.PacketType.getDefaultInstance()) {
          getTypeBuilder().mergeFrom(value);
        } else {
          type_ = value;
        }
      } else {
        typeBuilder_.mergeFrom(value);
      }
      if (type_ != null) {
        bitField0_ |= 0x00000002;
        onChanged();
      }
      return this;
    }
<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