Racket retaining in 2019 Panamerican games

Watching the 2019 edition of the Panamerican games, I noticed that a team match started with a double and from than the individuals followed. Now after finishing the doubles, the rackets were handed over to the empire only to be returned to the player when he was to start his single match. 

QUESTION: 

Is this just racquet control or is it to prevent eventual racquet switching, is the player then not allowed to change rackets between individual and double matches in the team event.

Hi Rene,

The umpire will keep the racket between matches because the rackets have been tested prior to the team's match.  Therefore the player is not allowed to change it with a racket that hasn't been tested.

A player may have two rackets tested prior to the start if they are going to play two matches within the team's match.