Execute JavaScript anywhere in the scenario

<?xml version="1.0" encoding="UTF-8" ?>
<scenario>
     <name>Execute JavaScript</name>
     <script>execute_javascript</script>
     <driver name="com.toolsverse.etl.driver.GenericFileDriver" />
     <beforetasks>
          <task noconnection="true">
               <name>security</name>
               <class>com.toolsverse.etl.core.task.common.ScriptTask</class>
               <code>
                    <![CDATA[
                    /* 
                    When ScriptTask is attached to the source or desination you can use 
                    dataSet varibale, where dataSet is a source or desination dataset. You can
                    manipulate dataset at you will. 
                    */
                    
                    importPackage(java.text);
                    importPackage(java.util);

importPackage(javax.crypto);
                    importPackage(javax.crypto.spec);

importPackage(org.apache.commons.codec.binary);

importPackage(com.toolsverse.config);

var soapUserId = SystemConfig.instance().getSystemProperty('requestUserId');
                    var soapSecretKey = SystemConfig.instance().getSystemProperty('soapSecretKey');

var df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");
                    var text = df.format(new java.util.Date());
                    var requestTimestamp = text.substring(0, 22) + ":" + text.substring(22);           
                    var encryptString = requestTimestamp + soapUserId;
             
                    var secretKey = new SecretKeySpec(new java.lang.String(soapSecretKey).getBytes(), "HmacSHA1");
                    var mac = Mac.getInstance("HmacSHA1");
                    mac.init(secretKey);
                    var rawHmac = mac.doFinal(new java.lang.String(encryptString).getBytes());
                    var hexChars = Hex.encodeHex(rawHmac);
                    var signature = new java.lang.String(hexChars);

SystemConfig.instance().setSystemProperty('requestSignature', signature);
                    SystemConfig.instance().setSystemProperty('requestTimestamp', requestTimestamp);
                    SystemConfig.instance().setSystemProperty('requestUserId', soapUserId);
                    ]]>
               </code>
               <variables>
                    <LANG value="JavaScript" />
               </variables>
          </task>
     </beforetasks>
</scenario>