}

        @Override
        public String getName() {
            return factory.getName();
        }

        @Override
        public String getFileExtension() {
            return factory.getFileExtension();
        }

        @Override
        public ChecksumCalculator getCalculator() {
            return new DefaultChecksumCalculator(factory.getAlgorithm());
        }

        }

        @Override
        public String getName() {
            return factory.getName();
        }

        @Override
        public String getFileExtension() {
            return factory.getFileExtension();
        }

        @Override
        public ChecksumCalculator getCalculator() {
            return new DefaultChecksumCalculator(factory.getAlgorithm());
        }

         * The checksum extension SHOULD NOT contain dot (".") character.
         * Example: "sha1".
         */
        @Nonnull
        String getFileExtension();

        /**
         * Each invocation of this method returns a new instance of calculator, never {@code null} value.
         */
        @Nonnull
        ChecksumCalculator getCalculator();
    }