code: @Override
      public final Graph convert(final From toConvert) {
  
          // Handle nulls
          if (toConvert == null && !acceptsNullValues()) {
              throw new IllegalArgumentException("Converter ["
                      + getClass().getName() + "] cannot accept null 'toConvert' arguments.");
          }
  
          // All Done
          return doConvert(toConvert);
      }
docs: {@inheritDoc}