Built in PQ function to add items at the end of the list?

[smpa01]

Is there any PQ built in functionality that adds an item to the end of the list?

To elaborate, my initial list is following = {{1,2,3},{"A","B","C"}}

I want to add {1} at the end of the above list, I can currently do that by

let
    Source = {{1,2,3},{"A","B","C"}},
    Custom1 = List.InsertRange(Source,List.Count(Source),{1})
in
    Custom1

But, I want to avoid writing Custom1 if there is a built-in functionality, something like following 

let
    Source = {{1,2,3},{"A","B","C"}},
    Custom1 = List.addAtTheEnd(Source,{1})
in
    Custom1

where the function figures out where to add the item by iteslf on the funtion call itself rather then me pointing it at the index position in 

List.InsertRange(<list>, <index>, <values>)

[p45cal]

I know this is an old one, but

let
    Source = {{1,2,3},{"A","B","C"}},
    Custom1 = Source & {1}
in
    Custom1

gives the same result, as does:

Custom1 = List.Combine({Source,{1}})

[Vera_33 · Accepted solution]

Hi @smpa01 

I don't see a built-in one, but you can write one custom function like this

let
    Source = {{1,2,3},{"A","B","C"}},
    fxListaddAtTheEnd = (SourceList,newValue)=>List.InsertRange(SourceList,List.Count(SourceList),newValue),
    Custom1 = fxListaddAtTheEnd(Source,{1})
in
    Custom1