<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema' elementFormDefault="unqualified"  targetNamespace="http://www.secondSchema" xmlns:ss="http://www.secondSchema">
  <xs:element name="realTag1" type="xs:string" />
  <xs:element name="realTag2" type="xs:string" />
  <xs:element name="realTag3" type="xs:string" />
  <xs:attribute name="attr1" type="xs:string" />
  <xs:attribute name="attr2" type="xs:integer" />

  <xs:attribute name="attr3" type="ss:unionType" />
  <xs:attribute name="attr4" type="ss:unionType" />
 
  <xs:simpleType name="unionType" >
    <xs:union memberTypes="xs:integer xs:string" />
  </xs:simpleType>

</xs:schema>