@Override
    public void visitPyAssignmentStatement(PyAssignmentStatement node) {
      final PyExpression value = node.getAssignedValue();
      if (value instanceof PyCallExpression) {
        final PyType type = myTypeEvalContext.getType(value);
        final PyExpression callee = ((PyCallExpression) value).getCallee();

        if (type instanceof PyNoneType && callee != null) {
          final PyTypeChecker.AnalyzeCallResults analyzeCallResults =
              PyTypeChecker.analyzeCall(((PyCallExpression) value), myTypeEvalContext);
          if (analyzeCallResults != null) {
            final PyCallable callable = analyzeCallResults.getCallable();
            if (PySdkUtil.isElementInSkeletons(callable)) {
              return;
            }
            if (callable instanceof PyFunction) {
              final PyFunction function = (PyFunction) callable;
              // Currently we don't infer types returned by decorators
              if (hasInheritors(function) || PyUtil.hasCustomDecorators(function)) {
                return;
              }
            }
            registerProblem(
                node,
                PyBundle.message("INSP.none.function.assignment", callee.getName()),
                new PyRemoveAssignmentQuickFix());
          }
        }
      }
    }
 /**
  * Looks for two standard decorators to a function, or a wrapping assignment that closely follows
  * it.
  *
  * @return a flag describing what was detected.
  */
 @Nullable
 public Modifier getModifier() {
   String deconame = getClassOrStaticMethodDecorator();
   if (PyNames.CLASSMETHOD.equals(deconame)) {
     return CLASSMETHOD;
   } else if (PyNames.STATICMETHOD.equals(deconame)) {
     return STATICMETHOD;
   }
   // implicit staticmethod __new__
   PyClass cls = getContainingClass();
   if (cls != null && PyNames.NEW.equals(getName()) && cls.isNewStyleClass()) {
     return STATICMETHOD;
   }
   //
   if (getStub() != null) {
     return getWrappersFromStub();
   }
   String func_name = getName();
   if (func_name != null) {
     PyAssignmentStatement assignment =
         PsiTreeUtil.getNextSiblingOfType(this, PyAssignmentStatement.class);
     if (assignment != null) {
       for (Pair<PyExpression, PyExpression> pair : assignment.getTargetsToValuesMapping()) {
         PyExpression value = pair.getSecond();
         if (value instanceof PyCallExpression) {
           PyExpression target = pair.getFirst();
           if (target instanceof PyTargetExpression && func_name.equals(target.getName())) {
             Pair<String, PyFunction> interpreted =
                 interpretAsModifierWrappingCall((PyCallExpression) value, this);
             if (interpreted != null) {
               PyFunction original = interpreted.getSecond();
               if (original == this) {
                 String wrapper_name = interpreted.getFirst();
                 if (PyNames.CLASSMETHOD.equals(wrapper_name)) {
                   return CLASSMETHOD;
                 } else if (PyNames.STATICMETHOD.equals(wrapper_name)) {
                   return STATICMETHOD;
                 }
               }
             }
           }
         }
       }
     }
   }
   return null;
 }
 private static boolean isAbstract(@NotNull PyClass pyClass) {
   final PyType metaClass =
       pyClass.getMetaClassType(
           TypeEvalContext.userInitiated(pyClass.getProject(), pyClass.getContainingFile()));
   if (metaClass instanceof PyClassLikeType
       && PyNames.ABC_META_CLASS.equals(metaClass.getName())) {
     return true;
   }
   if (metaClass == null) {
     final PyExpression metaClassExpr =
         as(pyClass.getMetaClassExpression(), PyReferenceExpression.class);
     if (metaClassExpr != null && PyNames.ABC_META_CLASS.equals(metaClassExpr.getName())) {
       return true;
     }
   }
   for (PyFunction method : pyClass.getMethods(false)) {
     if (PyUtil.isDecoratedAsAbstract(method)) {
       return true;
     }
   }
   return false;
 }