Jextract "splits" the header class (e.g. foo_h) into multiple classes (e.g. foo_h, foo_h_1, foo_h_2, ...). The main header class extends all the others (e.g. foo_h extends foo_h_1), so that simply (statically) importing everything in that class will suffice.

For this reason, only foo_h should be made public. All the other numbered header classes should be considered as part of the implementation.