public Builder clearOldestEstimatedArrivalTime() {
      bitField0_ = (bitField0_ & ~0x00000002);
      oldestEstimatedArrivalTime_ = null;
      if (oldestEstimatedArrivalTimeBuilder_ != null) {
        oldestEstimatedArrivalTimeBuilder_.dispose();
        oldestEstimatedArrivalTimeBuilder_ = null;
      }
      onChanged();
      return this;
    }
<pre>
Output only. An estimation of the nearest time in the future where a task
in the queue is scheduled to be executed.
</pre>

<code>
.google.protobuf.Timestamp oldest_estimated_arrival_time = 2 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-tasks/proto-google-cloud-tasks-v2beta3/src/main/java/com/google/cloud/tasks/v2beta3/QueueStats.java