public com.google.storagetransfer.v1.proto.TransferTypes.Schedule.Builder
          getScheduleBuilder() {
        bitField0_ |= 0x00000100;
        onChanged();
        return getScheduleFieldBuilder().getBuilder();
      }
<pre>
Specifies schedule for the transfer job.
This is an optional field. When the field is not set, the job never
executes a transfer, unless you invoke RunTransferJob or update the job to
have a non-empty schedule.
</pre>

<code>.google.storagetransfer.v1.Schedule schedule = 5;</code>
java-storage-transfer/proto-google-cloud-storage-transfer-v1/src/main/java/com/google/storagetransfer/v1/proto/TransferTypes.java