code: protected void removeFilters(EventCallBackStruct cb_struct) throws DevFailed {
          try {
              EventChannelStruct ec_struct = channel_map.get(cb_struct.channel_name);
              if (ec_struct != null) {
                  StructuredProxyPushSupplier supplier =
                          ec_struct.structuredProxyPushSupplier;
  
                  Filter filter = supplier.get_filter(cb_struct.filter_id);
                  if (filter != null) {
                      supplier.remove_filter(cb_struct.filter_id);
                      filter.destroy();
                  }
              }
          } catch (FilterNotFound e) {
              Except.throw_event_system_failed("API_EventNotFound",
                      "Failed to unsubscribe event, caught exception while calling remove_filter()" +
                              " (hint: check notification daemon is running)",
                      "EventConsumer.unsubscribe_event()");
          }
      }
docs: ===============================================================