4 Gallons of Water

You have two buckets, one holds exactly 5 gallons and the other 3 gallons.

How can you measure 4 gallons of water into the 5 gallon bucket?

(Assuming you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

Spoiler

Fill up the 5 gallon bucket.
Pour it into 3 gallon bucket, leaving 2 gallons.
Empty out the 3 gallon bucket.
Pour the 2 gallons in the 5 gallon bucket into the 3 gallon bucket.
Fill up the 5 gallon bucket and pour it into the 3 gallon bucket until it\’s full, leaving 4 gallons in the 5 gallon bucket.