Question:
Who was the chair of National Party of Australia in Apr, 2019?

Context:
 Warren Truss is the chair of National Party of Australia from Dec, 2007 to Feb, 2016. 
 Michael McCormack is the chair of National Party of Australia from Feb, 2016 to Dec, 2022. 
 Barnaby Joyce is the chair of National Party of Australia from Feb, 2016 to Feb, 2016.

Answer:
Question:
Who was the chair of National Party of Australia in Apr, 2019?

Context:
 Warren Truss is the chair of National Party of Australia from Dec, 2007 to Feb, 2016. 
 Michael McCormack is the chair of National Party of Australia from Feb, 2016 to Dec, 2022. 
 Barnaby Joyce is the chair of National Party of Australia from Feb, 2016 to Feb, 2016.

Answer:
user
Michael McCormack
assistant
Question:
Who was the chair of National Party of Australia in Apr, 2019?

Context:
 Warren Truss is the chair of National Party of Australia from Dec, 2007 to Feb, 2016. 
 Michael McCormack is the chair of National Party of Australia from Feb, 2016 to Dec, 2022. 
 Barnaby Joyce is the chair of National Party of Australia from Feb, 2016 to Feb, 2016.

Answer:
user
Barnaby Joyce
Warren Truss
assistant
Question:
Who was the chair of National Party of Australia in Apr, 2019?

Context:
 Warren Truss is the chair of National Party of Australia from Dec, 2007 to Feb, 2016. 
 Michael McCormack is the chair of National Party of Australia from Feb, 2016 to Dec, 2022. 
 Barnaby Joyce is the chair of National Party of Australia from Feb, 2016 to Feb, 2016.

Answer:
user
Michael McCormack
assistant