code: public void updateTenant(Tenant updatedTenant) {
          assert m_tenant.getName().equals(updatedTenant.getName());
          m_tenant = updatedTenant;
      }
docs: Update this DBService's Tenant with the given one. This is called when the tenant's
  definition has been updated in an upward-compatible way, such as adding or removing
  users.
  
  @param updatedTenant Updated {@link Tenant}.