GetUser Methods for Entity Framework MVC3 Razor Custom Member Provider C# Using LINQ

public override MembershipUser GetUser(object providerUserKey, bool userIsOnline)
{
    using (var context = new SSSEntities())
    {
        UserProfile u = context.UserProfiles
                    .SingleOrDefault(up => up.UserId == Convert.ToInt32(providerUserKey));
        MembershipUser membershipUser = GetMembershipUser(u);
        return membershipUser;
    }
}
public override MembershipUser GetUser(string username, bool userIsOnline)
{
    using (var context = new SSSEntities())
    {
        UserProfile u = context.UserProfiles
            .SingleOrDefault(up => up.UserName == username);
        MembershipUser membershipUser = GetMembershipUser(u);
        return membershipUser;
    }
}
// custom method to return a UserProfile
public UserProfile GetUser(string username)
{
    using (var context = new SSSEntities())
    {
        UserProfile u = context.UserProfiles
            .SingleOrDefault(up => up.UserName == username);
        return u;
    }
}
// custom method to return a UserProfile
public UserProfile GetUser(object providerUserKey)
{
    using (var context = new SSSEntities())
    {
        UserProfile u = context.UserProfiles
                    .SingleOrDefault(up => up.UserId == Convert.ToInt32(providerUserKey));
        return u;
    }
}