SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test
   Function isZeroOrNull (children 1)
    ExpressionList (children 1)
     Function equals (children 1)
      ExpressionList (children 2)
       Identifier x
       Literal \'xyz\'
