public class SinglePartitionWithoutOffsetsSystemAdmin
A simple helper admin class that defines a single partition (partition 0) for
a given system. The metadata uses null for all offsets, which means that the
stream doesn't support offsets, and will be treated as empty. This class
should be used when a system has no concept of partitioning or offsets, since
Samza needs at least one partition for an input stream, in order to read it.