code: public static <T extends Descriptor> T create(final Class<T> type, final String descriptorName)
          throws IllegalArgumentException {
          // Precondition checks
          if (type == null) {
              throw new IllegalArgumentException("type must be specified");
          }
  
          // Create
          return DescriptorInstantiator.createFromUserView(type, descriptorName);
      }
docs: Creates a new named {@link Descriptor} instance. If the name specified is null, the default name for this type
  will be assigned.
  
  @param <T>
  @param type
  @param descriptorName
  the descriptor name
  @return
  @throws IllegalArgumentException
  If the type is not specified