code: @Nonnull
    public static <ENUMTYPE extends Enum <ENUMTYPE> & IHasName> ENUMTYPE getFromNameOrThrow (@Nonnull final Class <ENUMTYPE> aClass,
                                                                                             @Nullable final String sName)
    {
      final ENUMTYPE aEnum = getFromNameOrNull (aClass, sName);
      if (aEnum == null)
        throw new IllegalArgumentException ("Failed to resolve name " + sName + " within class " + aClass);
      return aEnum;
    }
docs: Get the enum value with the passed name. If no such name is present, an
  {@link IllegalArgumentException} is thrown.
  
  @param <ENUMTYPE>
  The enum type
  @param aClass
  The enum class
  @param sName
  The name to search
  @return The enum item with the given name. Never <code>null</code>.
  @throws IllegalArgumentException
  if no enum item with the given name is present