public Builder setRecommendedNextDiff(com.google.protobuf.Timestamp value) {
      if (recommendedNextDiffBuilder_ == null) {
        if (value == null) {
          throw new NullPointerException();
        }
        recommendedNextDiff_ = value;
      } else {
        recommendedNextDiffBuilder_.setMessage(value);
      }
      bitField0_ |= 0x00000020;
      onChanged();
      return this;
    }
<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-v1beta1/src/main/java/com/google/webrisk/v1beta1/ComputeThreatListDiffResponse.java