Running tests on hat (7)

I believe the answer is:

stetson

'hat' is the definition.
(Stetson is an example)

'running tests on' is the wordplay.
'running' indicates anagramming the letters.
'tests' is an anagram of 'stets'.
'stets'+'on'='STETSON'

(Other definitions for stetson that I've seen before include "Hat, for Texan oil magnate, say" , "St Neots (anag.)" , "Large hat" , "Capital investment" , "capital item" .)

I've seen this clue in The Times.

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