docs: @SuppressWarnings("WeakerAccess")
      public Map<DeckReference, WaveformDetail> getLoadedDetails() {
          ensureRunning();
          if (!isFindingDetails()) {
              throw new IllegalStateException("WaveformFinder is not configured to find waveform details.");
          }
          // Make a copy so callers get an immutable snapshot of the current state.
          return Collections.unmodifiableMap(new HashMap<DeckReference, WaveformDetail>(detailHotCache));
      }