public Builder mergeValidUntilDuration(com.google.protobuf.Duration value) {
        if (validUntilDurationBuilder_ == null) {
          if (startTimingConstraintsCase_ == 1
              && startTimingConstraints_ != com.google.protobuf.Duration.getDefaultInstance()) {
            startTimingConstraints_ =
                com.google.protobuf.Duration.newBuilder(
                        (com.google.protobuf.Duration) startTimingConstraints_)
                    .mergeFrom(value)
                    .buildPartial();
          } else {
            startTimingConstraints_ = value;
          }
          onChanged();
        } else {
          if (startTimingConstraintsCase_ == 1) {
            validUntilDurationBuilder_.mergeFrom(value);
          } else {
            validUntilDurationBuilder_.setMessage(value);
          }
        }
        startTimingConstraintsCase_ = 1;
        return this;
      }
<pre>
A relative time after which resources should not be created.
If the request cannot be fulfilled by this time the request will be
failed.
</pre>

<code>.google.protobuf.Duration valid_until_duration = 1;</code>
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/QueuedResource.java