public void addRoles(Collection<String> roles) {
        if (this.roles == null) {
            this.roles = new HashSet<String>();
        }
        this.roles.addAll(roles);
    }
Adds (assigns) multiple roles to those associated with the account.  If the account doesn't yet have any roles, a
new roles collection (a Set) will be created automatically.

@param roles the roles to add to those associated with the account.
core/src/main/java/org/apache/shiro/authz/SimpleAuthorizationInfo.java