fix mismatching signatures of spawn

marl_factory_grid/modules/machines/groups.py

@@ -1,3 +1,5 @@
+from typing import Union, List, Tuple
+
 from marl_factory_grid.environment.groups.collection import Collection
 
 from .entitites import Machine
@@ -21,3 +23,4 @@ class Machines(Collection):
 
     def __init__(self, *args, **kwargs):
         super(Machines, self).__init__(*args, **kwargs)
+

marl_factory_grid/modules/machines/rules.py

@@ -13,8 +13,7 @@ class MachineRule(Rule):
         self.n_machines = n_machines
 
     def on_init(self, state, lvl_map):
-        # TODO Move to spawn!!!
-        state[m.MACHINES].add_items(Machine(pos) for pos in state.entities.empty_positions())
+        state[m.MACHINES].spawn(state.entities.empty_positions())
 
     def tick_pre_step(self, state) -> List[TickResult]:
         pass