Performer in part is tested (7)

I believe the answer is:

artiste

'performer' is the definition.
(artiste is a kind of performer)

'in part is tested' is the wordplay.
'in' says the answer is hidden in the clue.
'ARTISTE' can be found hidden inside 'part is tested'.

(Other definitions for artiste that I've seen before include "Trouper" , "Professional performer" , "Theatre performer" , "nightclub entertainer?" , "A sitter for creative person" .)

I've seen this clue in The Telegraph.

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