SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function base64Encode (children 1)
     ExpressionList (children 1)
      Function toFixedString (children 1)
       ExpressionList (children 2)
        Literal \'foo\'
        Literal UInt64_3