code: private boolean appendMap(StringBuilder builder, Object value)
      {
          boolean isPresent = false;
          if (value instanceof Map)
          {
              Map map = ((Map) value);
              isPresent = true;
              builder.append(Constants.OPEN_CURLY_BRACKET);
              for (Object mapKey : map.keySet())
              {
                  Object mapValue = map.get(mapKey);
                  // Allowing null keys.
                  appendValue(builder, mapKey != null ? mapKey.getClass() : null, mapKey, false);
                  builder.append(Constants.COLON);
                  // Allowing null values.
                  appendValue(builder, mapValue != null ? mapValue.getClass() : null, mapValue, false);
                  builder.append(Constants.COMMA);
              }
              if (!map.isEmpty())
              {
                  builder.deleteCharAt(builder.length() - 1);
              }
  
              builder.append(Constants.CLOSE_CURLY_BRACKET);
          }
          else
          {
              appendValue(builder, value.getClass(), value, false);
          }
          return isPresent;
      }
docs: Appends a object of type {@link java.util.List}
  
  @param builder
  the builder
  @param value
  the value
  @return true, if successful