Fix cache in tests

tests/test_chained_calls.py

@@ -10,6 +10,7 @@ import torch
 from petals import AutoDistributedConfig
 from petals.client.remote_sequential import RemoteSequential
 from petals.server.from_pretrained import load_pretrained_block
+from petals.utils.misc import DUMMY_KEY_PAST
 from test_utils import *
 
 
@@ -54,12 +55,13 @@ def test_chained_inference_exact_match(atol_inference=1e-4):
             outputs_inference.append(sess.step(inputs[:, i : i + 1, :]))
     outputs_inference = torch.cat(outputs_inference, dim=1)
 
+    dtype = torch.float32
     ref_blocks = [
-        load_pretrained_block(MODEL_NAME, 3, torch_dtype=torch.float32),
-        load_pretrained_block(MODEL_NAME, 4, torch_dtype=torch.float32),
+        load_pretrained_block(MODEL_NAME, 3, torch_dtype=dtype),
+        load_pretrained_block(MODEL_NAME, 4, torch_dtype=dtype),
     ]
     outputs_ref = []
-    caches = [None, None]
+    caches = [DUMMY_KEY_PAST.to(dtype), DUMMY_KEY_PAST.to(dtype)]
     for i in range(inputs.shape[1]):
         new_caches = []
         hidden_states = inputs[:, i : i + 1, :]