Help with groupByKey

[David Thomas]

I have an RDD of (K, Array[V]) pairs.

For example: ((key1, (1,2,3)), (key2, (3,2,4)), (key1, (4,3,2)))

How can I do a groupByKey such that I get back an RDD of the form (K,
Array[V]) pairs.

Ex: ((key1, (1,2,3,4,3,2)), (key2, (3,2,4)))