public static IQueryable <TUserRole> GetUserRoleQueryable <TKey, TUserRole>(this IIdentityContext_WithUserAndRoles <IIdentityRole <TKey>, TKey, TUserRole> context)
     where TKey : IEquatable <TKey>
     where TUserRole : class, IIdentityUserRole <TKey>
 => context.DbGetQueryable <TUserRole>();
 public static IIdentityDatabaseTable <TUserRole> GetUserRoleDatabaseTable <TKey, TUserRole>(this IIdentityContext_WithUserAndRoles <IIdentityRole <TKey>, TKey, TUserRole> context)
     where TKey : IEquatable <TKey>
     where TUserRole : class, IIdentityUserRole <TKey>
 => (IIdentityDatabaseTable <TUserRole>)context.GetUserRoleQueryable();
 public static IIdentityDatabaseTable <TRole> GetRoleDatabaseTable <TRole, TKey>(this IIdentityContext_WithUserAndRoles <TRole, TKey, IIdentityUserRole <TKey> > context)
     where TRole : class, IIdentityRoleWithConcurrency <TKey>
     where TKey : IEquatable <TKey>
 => (IIdentityDatabaseTable <TRole>)context.GetRoleQueryable();