12c SOA - Generate a random/unique number in XSLT ?

A unique ID needs to be assigned to every asynchronous request for tracking the status/uniquely identifying the request message. The ID needs to be universally unique (UUID) that is generated by the Oracle SOA Systems (ESB/BPEL) to correlate the request for future reference. You can take advantage of the XPath Extension Function orcl:generate-guid() that comes out-of-the box and format it accordingly like this: 

In XSLT:
<xsl:variable name="RandomNum">
    <xsl:value-of select="orcl:generate-guid()"/>
   </xsl:variable>

In BPEL:
   <variables>
        <variable name="correlationID" type="xsd:string">
          <from>oraext:generate-guid()</from>
        </variable>
      </variables>