commit method
Enhance memory, return added part.
Implementation
ByteData commit(int size) {
assert(size > 0);
// Create new memory and copy old data into it
final nd = ByteData(lengthInBytes + size);
if (_data != null) {
_copy(nd, _data!);
}
// Return added memory
final res = nd.buffer.asByteData(lengthInBytes);
// Set
_data = nd;
assert(res.lengthInBytes == size);
return res;
}