public long getFileOffset() {
        return fileOffset;
    }
Returns the optional offset in the specified file, at which to begin
uploading data for this part. If not specified, data will be read from
the beginning of the file.

@return The optional offset in the specified file, at which to begin
        uploading data for this part. If not specified, data will be read
        from the beginning of the file.
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/UploadPartRequest.java