@Override
        protected SubjectContext newSubjectContextInstance() {
            return new DefaultWebSubjectContext();
        }
Overrides the parent implementation to return a new instance of a
{@link DefaultWebSubjectContext DefaultWebSubjectContext} to account for the additional request/response
pair.

@return a new instance of a {@link DefaultWebSubjectContext DefaultWebSubjectContext} to account for the
additional request/response pair.
web/src/main/java/org/apache/shiro/web/subject/WebSubject.java