code: public static IBitFingerprint makeBitFingerprint(final Map<String,Integer> features, int len) {
          return makeBitFingerprint(features, len, 1);
      }
docs: Convert a mapping of features and their counts to a binary fingerprint. A single bit is
  set for each pattern.
  
  @param features features to include
  @param len fingerprint length
  @return the continuous fingerprint
  @see #makeBitFingerprint(java.util.Map, int, int)