code: private void validateTenantUsers(TenantDefinition tenantDef) {
          for (UserDefinition userDef : tenantDef.getUsers().values()) {
              Utils.require(!Utils.isEmpty(userDef.getPassword()),
                            "Password is required; user ID=" + userDef.getID());
              userDef.setHash(PasswordManager.hash(userDef.getPassword()));
              userDef.setPassword(null);
          }
      }
docs: hashed format.