">   <xsl:variable name="targets" select="key('id',@linkend)"/>   <xsl:variable name="target" select="$targets[0]"/>    <xsl:call-template name="check.id.unique">     <xsl:with-param name="linkend" select="@linkend"/>   </xsl:call-template>    <fo:basic-link internal-destination="{@linkend}"                  xsl:use-attribute-sets="xref.properties">     <xsl:choose>       <xsl:when test="count(child::node())