Fix __call__.

jedi/evaluate/context.py

@@ -0,0 +1,30 @@
+class Context(object):
+    type = None # TODO remove
+
+    def __init__(self, evaluator, parent_context=None):
+        self._evaluator = evaluator
+        self.parent_context = parent_context
+
+    def get_parent_flow_context(self):
+        return self.parent_context
+
+    def get_root_context(self):
+        context = self
+        while True:
+            if context.parent_context is None:
+                return context
+            context = context.parent_context
+
+    def execute(self, arguments=None):
+        return self._evaluator.execute(self, arguments)
+
+
+class TreeContext(Context):
+    def eval_node(self, node):
+        return self._evaluator.eval_element(self, node)
+
+
+class FlowContext(TreeContext):
+    def get_parent_flow_context(self):
+        if 1:
+            return self.parent_context