code: @Override
      public void writeObjectFieldValueSeparator(JsonGenerator jg)
          throws IOException, JsonGenerationException
      {
          if (_spacesInObjectEntries) {
              jg.writeRaw(" : ");
          } else {
              jg.writeRaw(':');
          }
      }
docs: Method called after an object field has been output, but
  before the value is output.
  <p>
  Default handling (without pretty-printing) will output a single
  colon to separate the two. Pretty-printer is
  to output a colon as well, but can surround that with other
  (white-space) decoration.