boolean (@NotNull PsiClass aClass) { final PsiReferenceList implementsList = aClass.getImplementsList(); if (implementsList == null) { return false; } for (PsiJavaCodeReferenceElement aInterfaces : implementsList.getReferenceElements()) { PsiElement implemented = aInterfaces.resolve(); if (implemented instanceof PsiClass && CommonClassNames.JAVA_IO_SERIALIZABLE.equals(((PsiClass)implemented).getQualifiedName())) { return true; } } return false; }