public Builder mergeWritesDoneGracePeriod(com.google.protobuf.Duration value) {
        if (writesDoneGracePeriodBuilder_ == null) {
          if (((bitField0_ & 0x00000020) != 0)
              && writesDoneGracePeriod_ != null
              && writesDoneGracePeriod_ != com.google.protobuf.Duration.getDefaultInstance()) {
            getWritesDoneGracePeriodBuilder().mergeFrom(value);
          } else {
            writesDoneGracePeriod_ = value;
          }
        } else {
          writesDoneGracePeriodBuilder_.mergeFrom(value);
        }
        if (writesDoneGracePeriod_ != null) {
          bitField0_ |= 0x00000020;
          onChanged();
        }
        return this;
      }
<pre>
The grace period after which a `writes_done_request` is issued, that a
`WritesDone` is expected from the client.

The server is free to cancel the RPC should this expire.

A system default will be chosen if unset.
</pre>

<code>.google.protobuf.Duration writes_done_grace_period = 6;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/ReceiveEventsRequest.java