@Override
    public boolean equals(final Object object) {
        if (this == object) {
            return true;
        }
        if (object == null || getClass() != object.getClass()) {
            return false;
        }
        final HashedDataFeedKey that = (HashedDataFeedKey) object;
        return expiryDateEpochMs == that.expiryDateEpochMs
               && Objects.equals(hash, that.hash)
               && Objects.equals(salt, that.salt)
               && Objects.equals(hashAlgorithm, that.hashAlgorithm)
               && Objects.equals(streamMetaData, that.streamMetaData);
    }
Represents the hashed form of a Data Feed Key, i.e. where we only have the
hash of the key and not the key itself.
stroom-receive/stroom-receive-common/src/main/java/stroom/receive/common/HashedDataFeedKey.java