SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function transform (alias name) (children 1)
     ExpressionList (children 3)
      Identifier name
      Literal Array_[\'test\', \'b\']
      Literal Array_[\'\', NULL]
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Function CAST (alias name) (children 1)
            ExpressionList (children 2)
             Literal \'test\'
             Literal \'Nullable(FixedString(4))\'
