SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function length (children 1)
     ExpressionList (children 1)
      Function topK (children 2)
       ExpressionList (children 1)
        Identifier A
       ExpressionList (children 1)
        Literal UInt64_30
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier topXtest