Equivalent of collect() on DStream

[Stephen Boesch]

Given that collect() does not exist on DStream apparently my mental model
of Streaming RDD (DStream) needs correction/refinement.  So what is the
means to convert DStream data into a JVM in-memory representation.  All of
the methods on DStream i.e. filter, map, transform, reduce, etc generate
other DStream's, and not an in memory data structure.