Deprecate unused function walk_model

Author: ricardoV94

pymc/pytensorf.py

@@ -190,6 +190,8 @@ def walk_model(
     expand_fn
         A function that returns the next variable(s) to be traversed.
     """
+    warnings.warn("walk_model will be removed in a future relase of PyMC", FutureWarning)
+
     if stop_at_vars is None:
         stop_at_vars = set()
 

tests/test_pytensorf.py

@@ -281,21 +281,24 @@ def test_walk_model():
 
     test_graph = pt.exp(e + 1)
 
-    res = list(walk_model((test_graph,)))
+    with pytest.warns(FutureWarning):
+        res = list(walk_model((test_graph,)))
     assert a in res
     assert b in res
     assert c in res
     assert d in res
     assert e in res
 
-    res = list(walk_model((test_graph,), stop_at_vars={c}))
+    with pytest.warns(FutureWarning):
+        res = list(walk_model((test_graph,), stop_at_vars={c}))
     assert a not in res
     assert b not in res
     assert c in res
     assert d in res
     assert e in res
 
-    res = list(walk_model((test_graph,), stop_at_vars={b}))
+    with pytest.warns(FutureWarning):
+        res = list(walk_model((test_graph,), stop_at_vars={b}))
     assert a not in res
     assert b in res
     assert c in res