how to call Partial class example

[MetadataType(typeof(UserMetadata))]
public partial class User
{
    public class UserMetadata
    {
        [StringLength(50), Required]
        public object Name { get; set; }
        [StringLength(5)]
        public object Email { get; set; }
        [Range(0, 10)]
        public object Rating { get; set; }
    }
}

public partial class User
{
        [StringLength(50), Required]
        public object NameOfFriend { get; set; }
        [StringLength(5)]
        public object EmailOfFriend { get; set; }
        [Range(0, 10)]
        public object RatingOfResume { get; set; }
}