code: public static SipApplicationSessionKey getSipApplicationSessionKey(final String applicationName, final String id, final String appGeneratedKey) {
  		if (logger.isDebugEnabled()){
  			logger.debug("getSipApplicationSessionKey - applicationName=" + applicationName + ", id=" + id + ", appGeneratedKey=" + appGeneratedKey);
  		}
  		if(applicationName == null) {
  			throw new NullPointerException("the application name cannot be null for sip application session key creation");
  		}
  		return new SipApplicationSessionKey(
  				id,
  				applicationName,
  				appGeneratedKey);		
  	}
docs: Computes the sip application session key from the input parameters.
  The sip application session key will be of the form (UUID,APPNAME)
  @param applicationName the name of the application that will be the second component of the key
  @param id the Id composing the first component of the key
  @return the computed key
  @throws NullPointerException if one of the two parameters is null