code: private String getCacheKey(String[] keys, CmsDbContext dbc) {
  
          if (!dbc.getProjectId().isNullUUID()) {
              return "";
          }
          StringBuffer b = new StringBuffer(64);
          int len = keys.length;
          if (len > 0) {
              for (int i = 0; i < len; i++) {
                  b.append(keys[i]);
                  b.append('_');
              }
          }
          if (dbc.currentProject().isOnlineProject()) {
              b.append("+");
          } else {
              b.append("-");
          }
          return b.toString();
      }
docs: Return a cache key build from the provided information.<p>
  
  @param keys an array of keys to generate the cache key from
  @param dbc the database context for which to generate the key
  
  @return String a cache key build from the provided information