code: public static VM getVM(Model mo, int vmID) throws JSONConverterException {
          VM vm = new VM(vmID);
          if (!mo.contains(vm)) {
              throw new JSONConverterException("Undeclared vm '" + vmID + "'");
          }
          return vm;
      }
docs: Get a VM from its identifier.
  The VM is already a part of the model.
  
  @param mo the associated model to browse
  @param vmID the node identifier
  @return the resulting VM
  @throws JSONConverterException if there is no model, or if the VM is unknown.