SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function coalesce (children 1)
     ExpressionList (children 2)
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal \'123\'
        Literal \'Nullable(Decimal(40, 10))\'
      Literal UInt64_0
