undeclared identifier: 'HashSet' error occured in macro

[aiac]

Error: undeclared identifier: 'HashSet'
    
    
    nnkIdentDefs.newTree(
              newIdentNode("__tags"),
              newEmptyNode(),
              nnkCall.newTree(
                nnkBracketExpr.newTree(newIdentNode("HashSet"), 
newIdentNode("string"))
              ),
            )
    
    
    Run

Confirm that Import std/sets