@java.lang.Override
      public boolean hasValidUntilDuration() {
        return startTimingConstraintsCase_ == 1;
      }
<pre>
Optional. 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 [(.google.api.field_behavior) = OPTIONAL];
</code>

@return Whether the validUntilDuration field is set.
java-tpu/proto-google-cloud-tpu-v2/src/main/java/com/google/cloud/tpu/v2/QueuedResource.java