public void setHashService(HashService hashService) {
        this.hashService = hashService;
    }
Constructs a new PasswordService with a default hash service and the default
algorithm name {@value #DEFAULT_HASH_ALGORITHM}, a default hash format (shiro2) and
a default hash format factory.

<p>The default algorithm can change between minor versions and does not introduce
API incompatibility by design.</p>
core/src/main/java/org/apache/shiro/authc/credential/DefaultPasswordService.java