Allow for no tuples in aggregate
Allow for no tuples in aggregate

IBMStreams/streamsx.topology,ddebrunner/streamsx.topology,IBMStreams/streamsx.topology,ddebrunner/streamsx.topology,ddebrunner/streamsx.topology,ddebrunner/streamsx.topology,ddebrunner/streamsx.topology,IBMStreams/streamsx.topology,IBMStreams/streamsx.topology,IBMStreams/streamsx.topology,ddebrunner/streamsx.topology,IBMStreams/streamsx.topology,IBMStreams/streamsx.topology,ddebrunner/streamsx.topology