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The Content Upload service allows uploading files using multiple threads in parallel. To use multi-threading, the client must first call StartFileUpload() and obtain an upload token. The client then uploads chunks in multiple threads (using AppendChunk() with different parameters), specifying the partNumber and [int] partNumber and offset for each thread along with the same upload token. After the chunks are uploaded, the client must call CompleteFileUpload(). The client may also upload several different files while at the same time specifying different upload tokens.
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