docs: private void updateCacheId() {
  
          StringBuffer result = new StringBuffer(32);
          if (m_filterVisible) {
              result.append(" Vi");
          }
          if (m_filterTimerange) {
              result.append(" Ti");
          }
          switch (m_filterState) {
              case REQUIRED:
                  result.append(" Sr");
                  result.append(m_state);
                  break;
              case EXCLUDED:
                  result.append(" Sx");
                  result.append(m_state);
                  break;
              default:
                  // ignored
          }
          switch (m_filterFlags) {
              case REQUIRED:
                  result.append(" Fr");
                  result.append(m_flags);
                  break;
              case EXCLUDED:
                  result.append(" Fx");
                  result.append(m_flags);
                  break;
              default:
                  // ignored
          }
          switch (m_filterType) {
              case REQUIRED:
                  result.append(" Tr");
                  result.append(m_type);
                  break;
              case EXCLUDED:
                  result.append(" Tx");
                  result.append(m_type);
                  break;
              default:
                  // ignored
          }
          if (m_onlyFolders != null) {
              if (m_onlyFolders.booleanValue()) {
                  result.append(" Fo");
              } else {
                  result.append(" Fi");
              }
          }
          if (m_filterLastModified) {
              result.append(" Lt");
              result.append(m_modifiedAfter);
              result.append("-");
              result.append(m_modifiedBefore);
          }
          if (m_filterExpire) {
              result.append(" Ex");
              result.append(m_expireAfter);
              result.append("-");
              result.append(m_expireBefore);
          }
          if (m_filterRelease) {
              result.append(" Re");
              result.append(m_releaseAfter);
              result.append("-");
              result.append(m_releaseBefore);
          }
          m_cacheId = result.toString();
      }