public class Product
{
    public int ProductID { get; set; }
    public string ProductName { get; set; }
    public string Category { get; set; }
    public decimal UnitPrice { get; set; }
    public int UnitsInStock { get; set; }
}
    
public class Order
{
    public int OrderID { get; set; }
    public DateTime OrderDate { get; set; }
    public decimal Total { get; set; }
}

public class Customer
{
    public string CustomerID { get; set; }
    public string CompanyName { get; set; }
    public string Address { get; set; }
    public string City { get; set; }
    public string Region { get; set; }
    public string PostalCode { get; set; }
    public string Country { get; set; }
    public string Phone { get; set; }
    public string Fax { get; set; }
    public Order[] Orders { get; set; }
}
        
public class Supplier
{
    public string SupplierName { get; set; }
    public string Address { get; set; }
    public string City { get; set; }
    public string Country { get; set; }
}
        
public class CaseInsensitiveComparer : IComparer<string>
{
    public int Compare(string x, string y)
    {
        return string.Compare(x, y, StringComparison.OrdinalIgnoreCase);
    }
}
        
private class AnagramEqualityComparer : IEqualityComparer<string>
{
    public bool Equals(string x, string y)
    {
        return getCanonicalString(x) == getCanonicalString(y);
    }

    public int GetHashCode(string obj)
    {
        return getCanonicalString(obj).GetHashCode();
    }

    private string getCanonicalString(string word)
    {
        char[] wordChars = word.ToCharArray();
        Array.Sort<char>(wordChars);
        return new string(wordChars);
    }
}
owenG