private boolean registerAnnotationByNullAssignmentStatus(PsiVariable variable) {
        if (variableNeverAssignedNull(variable)) {
            registerNotNullAnnotation(variable);
            return true;
        } else if (variableSometimesAssignedNull(variable)) {
            registerNullableAnnotation(variable);
            return true;
        }

        return false;
    }
private boolean registerAnnotationByNullAssignmentStatus(PsiVariable variable)