SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function count (children 1)
     ExpressionList
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t1
   Function in (children 1)
    ExpressionList (children 2)
     Function CAST (children 1)
      ExpressionList (children 2)
       Identifier c1
       Literal \'Nullable(String)\'
     Subquery (children 1)
      SelectWithUnionQuery (children 1)
       ExpressionList (children 2)
        SelectQuery (children 1)
         ExpressionList (children 1)
          Literal \'BBBBBB\'
        SelectQuery (children 1)
         ExpressionList (children 1)
          Literal NULL