The data.extend method. It's the primary way to add prototypes to the data table.
The method has two positional function parameters:
self :: Data?: Usually provided by calling data:extend(otherdata), which is syntax sugar for data.extend(data, otherdata).otherdata :: array[AnyPrototype]: A continuous array of non-abstract prototypes.The data.extend method can also be called with only the otherdata argument by calling it directly on data: data.extend(otherdata).
builtin