code: @Override
      public Character doDeserialize( JsonReader reader, JsonDeserializationContext ctx, JsonDeserializerParameters params ) {
          if ( JsonToken.NUMBER.equals( reader.peek() ) ) {
              return (char) reader.nextInt();
          } else {
              String value = reader.nextString();
              if ( value.isEmpty() ) {
                  return null;
              }
              return value.charAt( 0 );
          }
      }
docs: {@inheritDoc}