Merge "enhance AbstractMetricLogFilter"

diff --cc reference/logging-filter/logging-filter-base/src/main/java/org/onap/logging/filter/base/AbstractMetricLogFilter.java
index fc67460,23d83fb..79069c1
--- 1/reference/logging-filter/logging-filter-base/src/main/java/org/onap/logging/filter/base/AbstractMetricLogFilter.java
--- 2/reference/logging-filter/logging-filter-base/src/main/java/org/onap/logging/filter/base/AbstractMetricLogFilter.java
+++ b/reference/logging-filter/logging-filter-base/src/main/java/org/onap/logging/filter/base/AbstractMetricLogFilter.java
@@@ -62,9 -63,12 +63,13 @@@ public abstract class AbstractMetricLog
          }
      }
  
+     protected void additionalPre(Request request, RequestHeaders requestHeaders) {
+         // override to add application specific logic
+     }
+ 
      protected void setupHeaders(Request clientRequest, RequestHeaders requestHeaders) {
          String requestId = extractRequestID();
 +        String invocationId = UUID.randomUUID().toString();
          addHeader(requestHeaders, ONAPLogConstants.Headers.REQUEST_ID, requestId);
          addHeader(requestHeaders, Constants.HttpHeaders.HEADER_REQUEST_ID, requestId);
          addHeader(requestHeaders, Constants.HttpHeaders.TRANSACTION_ID, requestId);