Builder () { if (chunkBuilder_ == null) { if (fileHandleOrBufferCase_ == 2) { fileHandleOrBufferCase_ = 0; fileHandleOrBuffer_ = null; onChanged(); } } else { if (fileHandleOrBufferCase_ == 2) { fileHandleOrBufferCase_ = 0; fileHandleOrBuffer_ = null; } chunkBuilder_.clear(); } return this; }