SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function toNullable (alias os_name) (children 1)
     ExpressionList (children 1)
      Identifier os_name
    Function count (children 1)
     ExpressionList
   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 os_name) (children 1)
            ExpressionList (children 2)
             Literal \'iphone\'
             Literal \'Enum8(\\\'iphone\\\' = 1, \\\'android\\\' = 2)\'
   ExpressionList (children 1)
    Identifier os_name