private com.google.protobuf.SingleFieldBuilderV3<
              com.google.type.Interval,
              com.google.type.Interval.Builder,
              com.google.type.IntervalOrBuilder>
          getIntervalFieldBuilder() {
        if (intervalBuilder_ == null) {
          intervalBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.type.Interval,
                  com.google.type.Interval.Builder,
                  com.google.type.IntervalOrBuilder>(
                  getInterval(), getParentForChildren(), isClean());
          interval_ = null;
        }
        return intervalBuilder_;
      }
<pre>
The start and end time of the reservation.
</pre>

<code>.google.type.Interval interval = 4;</code>
java-tpu/proto-google-cloud-tpu-v2alpha1/src/main/java/com/google/cloud/tpu/v2alpha1/Reservation.java