Recreating c# method in Java

I am converting methods from my C# selenium framework into a Java equivalent All is good except a particular method shown below

    public class BusinessUserDetails
    {
        public string Email { get; set; }
        public string BusinessId { get; set; }
    }

    public static BusinessUserDetails JoinExistingSmeInitialize(string email = null)
    {
        var rand = new Random();
        var randNumber = rand.Next(1, 9999999);
        email = email ?? "auto-test_" + randNumber + "@mailinator.com";
        return new BusinessUserDetails
        {
            Email = email,
        };

Im converting it to Java and have got this far

public class BusinessUserDetails
{
    private String Email;
    public final String getEmail()
    {
        return Email;
    }
    public final String setEmail(String value)
    {
        Email = value;
        return value;
    }

    private String BusinessId;
    public final String getBusinessId()
    {
        return BusinessId;
    }
    public final void setBusinessId(String value)
    {
        BusinessId = value;
    }

}

    public BusinessUserDetails JoinExistingSmeInitialize(String email) {
    Random rand = new Random();
    int randNumber = rand.nextInt(9999999);
    email = (email != null) ? email : "auto-test_" + randNumber + "@mailinator.com";

    }

The one i cant seem to convert is this

        return new BusinessUserDetails
    {
        Email = email,
    };

any help would be appreciated!