IDL / XSD element with maxOccurs=3, how to access?

I'm using the Java APIs and have generated code from a supplied IDL.  The XSD defines the message type as a sequence of elements of type "x" having maxOccurs="3" .   How do I parse the indeterminate number of elements in my on_data_available(DataReader reader) method?

IDL / XSD

<xs:complexType name="My.XType">
<xs:sequence>
<xs:element name="Y" type="My.YType" maxOccurs="3">
<xs:annotation>
<xs:documentation>maximum of 3 occurencees</xs:documentation>
</xs:annotation>
</xs:element>
</xs:sequence>
</xs:complexType>


<xs:element name="X" type="My.XType">
<xs:annotation>
<xs:documentation>XLocation information</xs:documentation>
</xs:annotation>
</xs:element>

Code:

// ************************************************************************
// Implementation of the methods described in DataReaderListener interface
// ************************************************************************
public void on_data_available(DataReader reader) {

XTypeDataReader xReader = XTypeDataReader reader;

try
{
xReader.take(
_dataSeq,
_infoSeq,
ResourceLimitsQosPolicy.LENGTH_UNLIMITED,
SampleStateKind.ANY_SAMPLE_STATE,
ViewStateKind.ANY_VIEW_STATE,
InstanceStateKind.ANY_INSTANCE_STATE);

/* We process all the obtained samples for a particular instance */
for (int i = 0; i < _dataSeq.size(); ++i)
{
/* We first check if the sample includes valid data */
SampleInfo info = (SampleInfo)_infoSeq.get(i);
if (info.valid_data)
{
processData((XType)_dataSeq.get(i));
}
}
} catch (RETCODE_NO_DATA noData) {
// No data to process

} finally {
targetReader.return_loan(_dataSeq, _infoSeq);
}
}

/**************************************************************************
* Called for every valid sample received from DDS. */
private void processData(XType instance)
{

double dd = instance.XType.YType.value.double;

# how do I get the values from the other elements of YType (iterate through them?)

}