code: public boolean isReadOnlyRequest( final String requestId ) {
          if ( _log.isDebugEnabled() ) {
              _log.debug( "Asked for readonly request: " + requestId + " ("+ _readOnlyRequests.containsKey( requestId ) +")" );
          }
          // TODO: add some threshold
          return _readOnlyRequests.containsKey( requestId );
      }
docs: Determines, if the given requestURI is a readOnly request and not blacklisted as a modifying request.
  @param requestId the request uri to check
  @return <code>true</code> if the given request uri can be regarded as read only.