code: public static String footprint(String stringToFootprint) {
  		try {
  			MessageDigest md = MessageDigest.getInstance("SHA-1");
  			return byteArrayToHexString(md.digest(stringToFootprint.getBytes()));
  		}
  		catch (NoSuchAlgorithmException nsae) {
  			LOGGER.warn("Unable to calculate the footprint for string [{}].", stringToFootprint);
  			return null;
  		}	
  	}
docs: Calculate a footprint of a string
  
  @param stringToFootprint The string for which the footprint is calculated
  @return The footprint calculated