Moved ParamScheduler tests to core

tests/ignite/handlers/conftest.py

@@ -0,0 +1,32 @@
+import pytest
+import torch
+
+
+@pytest.fixture()
+def dummy_model_factory():
+    class DummyModel(torch.nn.Module):
+        def __init__(self):
+            super(DummyModel, self).__init__()
+            self.fc1 = torch.nn.Linear(10, 10)
+            self.fc2 = torch.nn.Linear(12, 12)
+            self.fc1.weight.data.zero_()
+            self.fc1.bias.data.zero_()
+            self.fc2.weight.data.fill_(1.0)
+            self.fc2.bias.data.fill_(1.0)
+
+    def get_dummy_model(with_grads=True, with_frozen_layer=False):
+        model = DummyModel()
+        if with_grads:
+            model.fc2.weight.grad = torch.zeros_like(model.fc2.weight)
+            model.fc2.bias.grad = torch.zeros_like(model.fc2.bias)
+
+            if not with_frozen_layer:
+                model.fc1.weight.grad = torch.zeros_like(model.fc1.weight)
+                model.fc1.bias.grad = torch.zeros_like(model.fc1.bias)
+
+        if with_frozen_layer:
+            for param in model.fc1.parameters():
+                param.requires_grad = False
+        return model
+
+    return get_dummy_model