@java.lang.Override
  public int getSerializedSize() {
    int size = memoizedSize;
    if (size != -1) return size;

    size = 0;
    if (((bitField0_ & 0x00000008) != 0)) {
      size += com.google.protobuf.CodedOutputStream.computeMessageSize(2, getRecommendedNextDiff());
    }
    if (responseType_
        != com.google.webrisk.v1.ComputeThreatListDiffResponse.ResponseType
            .RESPONSE_TYPE_UNSPECIFIED
            .getNumber()) {
      size += com.google.protobuf.CodedOutputStream.computeEnumSize(4, responseType_);
    }
    if (((bitField0_ & 0x00000001) != 0)) {
      size += com.google.protobuf.CodedOutputStream.computeMessageSize(5, getAdditions());
    }
    if (((bitField0_ & 0x00000002) != 0)) {
      size += com.google.protobuf.CodedOutputStream.computeMessageSize(6, getRemovals());
    }
    if (!newVersionToken_.isEmpty()) {
      size += com.google.protobuf.CodedOutputStream.computeBytesSize(7, newVersionToken_);
    }
    if (((bitField0_ & 0x00000004) != 0)) {
      size += com.google.protobuf.CodedOutputStream.computeMessageSize(8, getChecksum());
    }
    size += getUnknownFields().getSerializedSize();
    memoizedSize = size;
    return size;
  }
<pre>
The soonest the client should wait before issuing any diff
request. Querying sooner is unlikely to produce a meaningful diff.
Waiting longer is acceptable considering the use case.
If this field is not set clients may update as soon as they want.
</pre>

<code>.google.protobuf.Timestamp recommended_next_diff = 2;</code>
java-webrisk/proto-google-cloud-webrisk-v1/src/main/java/com/google/webrisk/v1/ComputeThreatListDiffResponse.java