code: @Override
      public boolean filter(Event event) {
          JXPathContext context = JXPathContext.newContext(event);
          Pointer pointer = context.getPointer(expression);
          return (Boolean)pointer.getValue();
      }
docs: /* (non-Javadoc)
  @see org.talend.esb.sam.common.spi.EventFilter#filter(org.talend.esb.sam.common.event.Event)