Get the end position of transfer range. The position is in bytes, and byte 0 is the first byte
of the file, N-1 is the last position in the file, where N is the length of the file in bytes.
the position in the file (in bytes) to indicate the end of range to retrieve. If equal to -1,
then this means that no end position is specified, and the download will continue to the end of file. If gt or eq 0,
but less than the getStartPosition() then this range specification is invalid. If greater than or
equal to N (where N is length of the file in bytes), then the remaining part of the given file will
be downloaded. If both getStartPosition() and getEndPosition() are valid, then
the number of bytes downloaded will be (endPosition - startPosition) + 1. So, for example: