public Builder setValidAfterDuration(com.google.protobuf.Duration value) {
        if (validAfterDurationBuilder_ == null) {
          if (value == null) {
            throw new NullPointerException();
          }
          startTimingConstraints_ = value;
          onChanged();
        } else {
          validAfterDurationBuilder_.setMessage(value);
        }
        startTimingConstraintsCase_ = 3;
        return this;
      }
<pre>
Optional. A relative time after which resources may be created.
</pre>

<code>
.google.protobuf.Duration valid_after_duration = 3 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-tpu/proto-google-cloud-tpu-v2/src/main/java/com/google/cloud/tpu/v2/QueuedResource.java