write some tests and stick grid and time in model and sim respectively as attrs. maybe the way to go? but we need to repeat them in all relevant packages in that case. we could maybe also do a decorator that adds grid/time via field_transformer? but that's probably too fancy

Author: wpbonelli

flopy4/mf6/gwf/__init__.py

@@ -5,6 +5,7 @@
 import imod
 import xarray as xr
 from attrs import define
+from flopy.discretization.grid import Grid
 from xattree import field, xattree
 
 from flopy4.mf6.gwf.chd import Chd
@@ -47,6 +48,7 @@ def budget(self):
     output: Output = attrs.field(
         default=attrs.Factory(lambda self: Gwf.Output(self), takes_self=True)
     )
+    grid: Grid = attrs.field(default=None)
 
     @define
     class NewtonOptions:

flopy4/mf6/simulation.py

@@ -1,5 +1,6 @@
 from pathlib import Path
 
+import attrs
 from xattree import field, xattree
 
 from flopy4.mf6.component import Component
@@ -8,6 +9,8 @@
 from flopy4.mf6.solution import Solution
 from flopy4.mf6.tdis import Tdis
 
+from flopy.discretization.modeltime import ModelTime
+
 
 @xattree
 class Simulation(Component):
@@ -16,3 +19,4 @@ class Simulation(Component):
     solutions: dict[str, Solution] = field()
     tdis: Tdis = field()
     sim_ws: Path = field(default=None)
+    time: ModelTime = attrs.field(default=None)