code: private DeleteSubnetResponseType deleteSubnet(final String subnetId) {
          DeleteSubnetResponseType ret = new DeleteSubnetResponseType();
          ret.setRequestId(UUID.randomUUID().toString());
          mockSubnetController.deleteSubnet(subnetId);
          return ret;
      }
docs: Handles "deleteSubnet" request to delete subnet and returns response with a subnet.
  @param subnetId Subnet Id.
  @return a DeleteSubnetResponseType with subnet.