code: public WaveformDetail requestWaveformDetailFrom(final DataReference dataReference) {
          ensureRunning();
          for (WaveformDetail cached : detailHotCache.values()) {
              if (cached.dataReference.equals(dataReference)) {  // Found a hot cue hit, use it.
                  return cached;
              }
          }
          return requestDetailInternal(dataReference, false);
      }
docs: Ask the specified player for the specified waveform detail from the specified media slot, first checking if we
  have a cached copy.
  
  @param dataReference uniquely identifies the desired waveform detail
  
  @return the waveform detail, if it was found, or {@code null}
  
  @throws IllegalStateException if the WaveformFinder is not running