code: public void setSubnetBlacklist(Iterable<Subnet> subnets) {
          if (subnets == null) {
              throw new NullPointerException("Subnets must not be null");
          }
          blacklist.clear();
          for (Subnet subnet : subnets) {
              block(subnet);
          }
      }
docs: Sets the subnets to be blacklisted.
  
  NOTE: this call will remove any previously blacklisted subnets.
  
  @param subnets an array of subnets to be blacklisted.