378 Bus line in api

Hi

There is data for a Bus with route number 378 in the data.
The route description is Putney Bridge - Mortlake
Departures commencing on 17th August.

Do you know what this is?

Route 378 actually started on Saturday 3rd. It does what the diverted 209 was doing but the 209 is once again running to the south side of the closed Hammersmith Bridge.I thinlk it changes opertaor on 17th, which must be some kind of record for a new route.