SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function avgWeighted (children 1)
     ExpressionList (children 2)
      Identifier x
      Identifier y
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 2)
         SelectQuery (children 1)
          ExpressionList (children 3)
           Literal NULL
           Literal UInt64_255 (alias x)
           Literal UInt64_1 (alias y)
         SelectQuery (children 1)
          ExpressionList (children 3)
           Identifier y
           Literal NULL (alias x)
           Literal UInt64_1 (alias y)
