How to force a line to execute in Power Query

[sesame5486]

I recently posted this question when my query would not refresh correctly. The query would only refresh correctly after I refreshed the preview.

To summarise the question and answer, the reason why the query would only refresh correctly after refreshing the preview was because one of the steps in the query was not referenced by the final step, but was essential for the API to work correctly (please see post for full details).

My question is simple: how do I force Power Query to execute a step even if that step is not referenced in the final step? To illustrate my point, how would I force Power Query to execute step "a = "123"," below?

let
   a = "123",
   b = "456"
in
   b

[slorin · Accepted solution]

Hi,

May be, 

let
  a = "123",
  b = "456",
  Choose = (chooseFirst as logical, first, second) => 
     if chooseFirst then first else second
in
  Choose(false, a, b)

https://bengribaudo.com/blog/2018/02/28/4391/power-query-m-primer-part5-paradigm

Stéphane