fetch
Synchronously fetch a chunk of data from a start and end byte offset. This method should be thread safe as it can be called from multiple threads simultaneously. In case of error, throw exception.
Parameters
start
An index into the data source indicating the first byte to include in the result buffer
end
An index into the data source indicating the first byte that will not be included in the result buffer. Must be larger than 'start', and less than or equal to the value returned by getSize().