Have reset state handlers go through a shared list

To make it hopefully easier to understand the commonality
of this function and its handlers have the handlers be
defined at the top of the function and use the common list
in the node iteration routine when resetting/matching.

Change-Id: I288eb548172b2f6f35e2bd90683f2065d3aa02dc

taskflow/engines/action_engine/runtime.py

@@ -98,18 +98,23 @@ class Runtime(object):
 
     def reset_nodes(self, nodes, state=st.PENDING, intention=st.EXECUTE):
         tweaked = []
+        node_state_handlers = [
+            (self.task_action, {'progress': 0.0}),
+            (self.retry_action, {}),
+        ]
         for node in nodes:
             if state or intention:
                 tweaked.append((node, state, intention))
             if state:
-                if self.task_action.handles(node):
-                    self.task_action.change_state(node, state,
-                                                  progress=0.0)
-                elif self.retry_action.handles(node):
-                    self.retry_action.change_state(node, state)
-                else:
-                    raise TypeError("Unknown how to reset atom '%s' (%s)"
-                                    % (node, type(node)))
+                handled = False
+                for h, kwargs in node_state_handlers:
+                    if h.handles(node):
+                        h.change_state(node, state, **kwargs)
+                        handled = True
+                        break
+                if not handled:
+                    raise TypeError("Unknown how to reset state of"
+                                    " node '%s' (%s)" % (node, type(node)))
             if intention:
                 self.storage.set_atom_intention(node.name, intention)
         return tweaked