getOrCreateOffset method
Can be used to write the data represented by this builder to the Builder and reuse the offset created in multiple tables.
Note that this method assumes you call it using the same Builder instance every time. The returned offset is only good for the Builder used in the first call to this method.
Implementation
int getOrCreateOffset(Builder fbBuilder) {
_firstOffset ??= finish(fbBuilder);
return _firstOffset!;
}