
xdmp:get-session-field-names() as xs:string*
  Returns a sequence of the HTTP session field names from the session
  created by the xdmp:login
   function. 
http://marklogic.com/xdmp/privileges/xdmp-get-session-field-names
xdmp:set-session-field
  
  function to set a named value in a session and the 
  xdmp:get-session-field
  
  function to return a value set in a session field.
xdmp:get-session-field-names()
=> ("user", "role", "action", "index")