code: public String getCompressor(String type) {
          if (mCompressionMap == null) {
              return null;
          }
  
          return mCompressionMap.get(type).toString();
      }
docs: Return the compressor used for the given storable.
  @param type Storable to compress
  @return String representation of the type of compression used. Available options are "NONE"
  for no compression and "GZIP" for gzip compression.