digest.update (MD5Encoder.toBytes((Date) what).getTime());
digest.update (MD5Encoder.toBytes(((Date) what).getTime()));
    public void dependsOn (Object what) {	if (digest == null) try {	    digest = MessageDigest.getInstance ("MD5");	} catch (NoSuchAlgorithmException nsa) {	    // MD5 should always be available	}	if (what == null) {	    digest.update (new byte[0]);	} else if (what instanceof Date) {	    digest.update (MD5Encoder.toBytes((Date) what).getTime());	} else if (what instanceof byte[]) {	    digest.update ((byte[]) what);	} else {	    String str = what.toString();	    if (str != null)	        digest.update (str.getBytes ());	    else	        digest.update (new byte[0]);	}    }