flush method
Flush any remaining buffered bytes.
Call this when the stream ends to get any remaining partial data. This may throw a FormatException if the buffer contains invalid UTF-8.
Implementation
String flush() {
if (_buffer.isEmpty) return '';
try {
final result = utf8.decode(_buffer);
_buffer.clear();
return result;
} catch (e) {
// Invalid UTF-8 sequence, clear buffer and return empty
_buffer.clear();
return '';
}
}