Here is a more complex
GroupedVirtuoso example displaying 500 users, grouped by the first letter of their name.
generateGroupedUsers is a dummy implementation that builds grouped data. The
users variable contains 500 user records, sorted by name.
groups variable contains the first letter groups ->
['A', 'B', 'C'].
groupCounts specifies how many items each group has ->
[ 20, 30, 15, 10 ].