3 Bean Salad

From Mom:

my favorite recipe with garbonzo beans is 3 bean salad

1 can garbonzo beans, drained
2 cans green beans, drained
1 can red kidney beans, drained
1/2 red onion chopped
dressing - 1/4 c. oil, 2 TB vinegar, 1/2 c. sugar - mix and pour over veggies,
- better if sits over night in fridge
- stir several times