SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function substring (children 1)
     ExpressionList (children 3)
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal \'abcdefgh\'
        Literal \'FixedString(8)\'
      Literal UInt64_2
      Literal Int64_-2