Fix some more context issues

jedi/inference/value/function.py

@@ -153,7 +153,7 @@ class MethodValue(FunctionValue):
         self.class_value = class_value
 
     def get_default_param_context(self):
-        return self.class_value
+        return self.class_value.as_context()
 
     def get_qualified_names(self):
         # Need to implement this, because the parent value of a method

jedi/inference/value/instance.py

@@ -473,7 +473,7 @@ class InstanceClassFilter(AbstractFilter):
         ]
 
     def __repr__(self):
-        return '<%s for %s>' % (self.__class__.__name__, self._class_filter.value)
+        return '<%s for %s>' % (self.__class__.__name__, self._class_filter.context)
 
 
 class SelfAttributeFilter(ClassFilter):

jedi/inference/value/iterable.py

@@ -292,12 +292,10 @@ class DictComprehension(ComprehensionMixin, Sequence):
     def py__simple_getitem__(self, index):
         for keys, values in self._iterate():
             for k in keys:
-                # TODO remove this isinstance.
-                if isinstance(k, compiled.CompiledObject):
-                    # Be careful in the future if refactoring, index could be a
-                    # slice.
-                    if k.get_safe_value(default=object()) == index:
-                        return values
+                # Be careful in the future if refactoring, index could be a
+                # slice object.
+                if k.get_safe_value(default=object()) == index:
+                    return values
         raise SimpleGetItemNotFound()
 
     def _dict_keys(self):