this.fileBackedStreamFactory = Preconditions.checkNotNull(builder.fileBackedStreamFactory,
"FiledBackedStreamFactory cannot be null");
this.assembledMessageCallback = Preconditions.checkNotNull(builder.assembledMessageCallback,
this.fileBackedStreamFactory = Preconditions.checkNotNull(builder.fileBackedStreamFactory,
"FiledBackedStreamFactory cannot be null");
this.assembledMessageCallback = Preconditions.checkNotNull(builder.assembledMessageCallback,