SimpleXML跳过属性

Test XML:

<?xml version="1.0" encoding="UTF-8"?>
<Transfer>
    <ABR recordLastUpdatedDate="20180329" replaced="N">
        <ABN status="ACT" ABNStatusFromDate="20000214">80007321682</ABN>
        <EntityType>
            <EntityTypeInd>PUB</EntityTypeInd>
            <EntityTypeText>Australian Public Company</EntityTypeText>
        </EntityType>
        <MainEntity>
            <NonIndividualName type="MN">
                <NonIndividualNameText>BLACK CABS COMBINED PTY LTD</NonIndividualNameText>
            </NonIndividualName>
            <BusinessAddress>
                <AddressDetails>
                    <State>VIC</State>
                    <Postcode>3166</Postcode>
                </AddressDetails>
            </BusinessAddress>
        </MainEntity>
    </ABR>
</Transfer>

PHP Script:

$f='test.xml';
$reader=new XMLReader();
$reader->open($f);
while($reader->read()){
    if($reader->nodeType==XMLReader::ELEMENT && $reader->name=='ABR'){
        $doc=new DOMDocument('1.0','UTF-8');
        $xml=simplexml_import_dom($doc->importNode($reader->expand(),true));
        print_r($xml);
    }
}
$reader->close();

PHP Output:

SimpleXMLElement Object
(
    [@attributes] => Array
        (
            [recordLastUpdatedDate] => 20180329
            [replaced] => N
        )

    [ABN] => 80007321682
    [EntityType] => SimpleXMLElement Object
        (
            [EntityTypeInd] => PUB
            [EntityTypeText] => Australian Public Company
        )

    [MainEntity] => SimpleXMLElement Object
        (
            [NonIndividualName] => SimpleXMLElement Object
                (
                    [@attributes] => Array
                        (
                            [type] => MN
                        )

                    [NonIndividualNameText] => BLACK CABS COMBINED PTY LTD
                )

            [BusinessAddress] => SimpleXMLElement Object
                (
                    [AddressDetails] => SimpleXMLElement Object
                        (
                            [State] => VIC
                            [Postcode] => 3166
                        )

                )

        )

)

The Problem:

The attributes for the ABN element (status and ABNStatusFromDate) are not in the output, even though other attributes are.

Please help me understand why those attributes in particular are missing.

PS - Dummy text so SO doesn't give me warnings about my post being mostly code

Answer: print_r is not meant to be used to display a SimpleXML object.

I can access the attribute directly via $xml->ABN['status'].