помогите найти ошибку
пытаюс сделать уникальным поле id
в итоге ставлю в хml 2 одинаковых айдишника и это валидируется без ошибок(( почему?
XSD
<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns=" http://www.w3.org/2001/XMLSchema"
targetNamespace=" http://www.example.com/"
xmlns:tns=" http://www.example.com/">
<element name="trains">
<complexType>
<sequence>
<element name="train" type="tns:Train" minOccurs="1" maxOccurs="unbounded" />
</sequence>
</complexType>
<unique name="uniqueId">
<selector xpath="trains/Train"/>
<field xpath="@id"/>
</unique>
</element>



<complexType name="Train">
<sequence>
<element name="traintype" type="tns:TrainType" />
</sequence>
<attribute name="id" type="integer" use="required" />
<attribute name="propulsion" type="tns:Propulsion" use="required" />
</complexType>

<complexType name="TrainType">
<sequence>
<element name="countpassengers" type="tns:CountPassengers" />
<element name="routname" type="tns:Routs" />
</sequence>
</complexType>

<simpleType name="Routs">
<restriction base="string">
<enumeration value="Brest-Minsk"/>
<enumeration value="Minsk-Moscow"/>
<enumeration value="Moscow-Piter"/>
</restriction>
</simpleType>

<simpleType name="CountPassengers">
<restriction base="integer">
<minInclusive value="50"/>
<maxInclusive value="500"/>
</restriction>
</simpleType>

<simpleType name="Propulsion">
<restriction base="string">
<enumeration value="Diesel"/>
<enumeration value="Electric"/>
<enumeration value="SteamLocomotive"/>
</restriction>
</simpleType>

</schema>


xml
<?xml version="1.0" encoding="UTF-8"?>
<tns:trains xmlns:tns=" http://www.example.com/" xmlns:xsi=" http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.example.com/ CommuterTrain.xsd ">
<train id="1" propulsion="Diesel">
<traintype>
<countpassengers>100</countpassengers>
<routname>Brest-Minsk</routname>
</traintype>
</train>
<train id="1" propulsion="Electric">
<traintype>
<countpassengers>100</countpassengers>
<routname>Brest-Minsk</routname>
</traintype>
</train>
</tns:trains>

спасибо