v1/test/src/schemas/includer2.xsd

<xs:schema
   xmlns:xs="http://www.w3.org/2001/XMLSchema"
   xmlns:tns="http://openuri.org/includer2"
   targetNamespace="http://openuri.org/includer2"
   elementFormDefault="qualified">

  <xs:include schemaLocation="included.xsd"/>

  <xs:element name="twochains">
    <xs:complexType>
      <xs:sequence>
        <xs:element ref="tns:chain" minOccurs="2" maxOccurs="2"/>
      </xs:sequence>
    </xs:complexType>
  </xs:element>

</xs:schema>