What is the relationship between Brian Hartzer and Westpac in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

There have been some excellent recent examples of this including the following appointments: Brian Hartzer at Westpac Banking Corp, Jon Sutton at Bank of Queensland, Ryan Stokes at Seven Group Holdings, Peter Tonagh at News Corp Australia and Chris Smith at CSL.

Answer: employer