pub fn startup(self, _ty: i32, mod_num: i32) -> Result<()> {
        for (name, val) in self.constants {
            val.register_constant(&name, mod_num)?;
        }

        self.classes.into_iter().map(|c| c()).for_each(|c| {
            c.register().expect("Failed to build class");
        });
        Ok(())
    }
Completes startup of the module. Should only be called inside the module
startup function.

# Errors

* Returns an error if a constant could not be registered.

# Panics

* Panics if a class could not be registered.
src/builders/module.rs