The collectDetailedInterfaceStats function is provided by JVppCore.  The use of this feature however seems unclear. The implementation in VPP (vpp/src/vnet/interface_stats.c) reads: "only ethernet HW interfaces are supported at this time".  

At this point statistics collection on interfaces can be switched on using functions such as wantPerInterfaceSimpleStats, wantPerInterfaceCombinedStats, etc.  Vpp will start sending statistics periodically in form of notifications. 
Feature collectDetailedInterfaceStats however seems to work differently.