private com.google.protobuf.SingleFieldBuilderV3<
              com.google.storagetransfer.v1.proto.TransferTypes.ReplicationSpec,
              com.google.storagetransfer.v1.proto.TransferTypes.ReplicationSpec.Builder,
              com.google.storagetransfer.v1.proto.TransferTypes.ReplicationSpecOrBuilder>
          getReplicationSpecFieldBuilder() {
        if (replicationSpecBuilder_ == null) {
          replicationSpecBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.storagetransfer.v1.proto.TransferTypes.ReplicationSpec,
                  com.google.storagetransfer.v1.proto.TransferTypes.ReplicationSpec.Builder,
                  com.google.storagetransfer.v1.proto.TransferTypes.ReplicationSpecOrBuilder>(
                  getReplicationSpec(), getParentForChildren(), isClean());
          replicationSpec_ = null;
        }
        return replicationSpecBuilder_;
      }
<pre>
Replication specification.
</pre>

<code>.google.storagetransfer.v1.ReplicationSpec replication_spec = 17;</code>
java-storage-transfer/proto-google-cloud-storage-transfer-v1/src/main/java/com/google/storagetransfer/v1/proto/TransferTypes.java