readIntoSync method Null safety
Synchronously reads into an existing List<int> from the file and returns the number of bytes read.
If start is present, the bytes will be filled into buffer from at
index start, otherwise index 0. If end is present, the
end - start bytes will be read into buffer, otherwise up to
buffer.length. If end == start nothing happens.
Throws a FileSystemException if the operation fails.
Implementation
int readIntoSync(List<int> buffer, [int start = 0, int? end]);