code: public String asUrlPart() {
          try {
              return encode(projectName) + "~" + encode(branchName) + "~" + id;
          } catch (UnsupportedEncodingException e) {
              String parameter = projectName + "~" + branchName + "~" + id;
              logger.error("Failed to encode ChangeId {}, falling back to unencoded {}", this, parameter);
              return parameter;
          }
      }
docs: As the part of the URL.
  
  @return the url part.