readByteSync method
Synchronously reads a single byte from the file.
If end-of-file has been reached -1 is returned.
Throws a FileSystemException if the operation fails.
Implementation
@override
int readByteSync() {
_assertIsOpen();
_assertIsReadable('readByteSync');
if (_position >= lengthSync()) {
throw FileSystemException('Cannot readByte at end of file', path);
}
return _file.bytes[_position++];
}