@java.lang.Override
      public com.google.storagetransfer.v1.proto.TransferTypes.PosixFilesystem getPosixDataSink() {
        if (posixDataSinkBuilder_ == null) {
          if (dataSinkCase_ == 13) {
            return (com.google.storagetransfer.v1.proto.TransferTypes.PosixFilesystem) dataSink_;
          }
          return com.google.storagetransfer.v1.proto.TransferTypes.PosixFilesystem
              .getDefaultInstance();
        } else {
          if (dataSinkCase_ == 13) {
            return posixDataSinkBuilder_.getMessage();
          }
          return com.google.storagetransfer.v1.proto.TransferTypes.PosixFilesystem
              .getDefaultInstance();
        }
      }
<pre>
A POSIX Filesystem data sink.
</pre>

<code>.google.storagetransfer.v1.PosixFilesystem posix_data_sink = 13;</code>

@return The posixDataSink.
java-storage-transfer/proto-google-cloud-storage-transfer-v1/src/main/java/com/google/storagetransfer/v1/proto/TransferTypes.java