code: @Override
      public long getLastModified() {
          long value = 0;
          try {
              value = this.url.openConnection().getLastModified();
          } catch (IOException e) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "getLastModified - caught IOException", e);
              }
              value = -1;
          }
  
          if (value == -1) { // exception caught
              value = 0; // 0 indicates unknown time
          } else if (value == 0) { // the connection succeeded, but the last modified date/time is unknown
              if (isUpdated()) { // do we need to update the lastModified?
                  value = System.currentTimeMillis();
                  setLastModified(value);
              }
          } else { // got last modified date/time from remote resource
              setLastModified(value);
          }
  
          return value;
      }
docs: {@inheritDoc}