ToLookup IEqualityComparer 参数始终为空

我偶然遇到了一个奇怪的问题，这对我来说并没有意义。

我有一个业务对象地址，其中包含属性位置（类型为 SqlGeography）。出于我的要求，我必须对位置进行查找，因为每个确切位置可能有多个地址。

由于 SqlGeography 是一种复杂的类型，我怀疑查找可能不起作用，因为它由于某种原因不基于位置坐标，所以我这样做了：

public class Address
{
    public Address(byte[] location)
    {
        Location = SqlGeography.Deserialize(new SqlBytes(location));
    }
    public SqlGeography Location { get; set; }
}
public class SqlGeographyComparer : IEqualityComparer<SqlGeography>
{
    public bool Equals(SqlGeography x, SqlGeography y)
    {
        // !!! always entered but for some reason x + y always null
        if (x == null && y == null)
            return true;
        if (x == null ^ y == null)
            return false;
        return x.STEquals(y).IsTrue;
    }
    public int GetHashCode(SqlGeography obj)
    {
        return obj.GetHashCode();
    }
}
class Program
{
    static void Main(string[] args)
    {
        var addresses = GetAddresses();
        // should be 2 but it's 3 results
        var addressesLookup = addresses.ToLookup(d => d.Location);
        // should be 2 but it's 3 results
        var addressesLookup2 = addresses.ToLookup(d => d.Location, new SqlGeographyComparer());
        Console.ReadLine();
    }
    private static IList<Address> GetAddresses()
    {
        //              230,16,0,0,1,12,213,97,212,23,126,78,72,64,109,51,198,37,82,163,32,64
        var result = new List<Address>();
        result.Add(new Address(new byte[] { 230, 16, 0, 0, 1, 12, 213, 97, 212, 23, 126, 78, 72, 64, 109, 51, 198, 37, 82, 163, 32, 64 }));
        result.Add(new Address(new byte[] { 230, 16, 0, 0, 1, 12, 213, 97, 212, 23, 126, 78, 72, 64, 109, 51, 198, 37, 82, 163, 32, 64 }));
        result.Add(new Address(new byte[] { 230, 16, 0, 0, 1, 12, 213, 97, 212, 23, 126, 78, 72, 64, 109, 51, 198, 37, 82, 163, 32, 63 }));
        return result;
    }
}

这是我没有听说过的关于 ToLookup 只是不将对象传递到给定比较器实例中的一些奇怪错误吗？！

    public int GetHashCode(SqlGeography obj)
    {
        unchecked
        {
            return ((obj.Lat.GetHashCode() * 397) ^ obj.Long.GetHashCode());
        }
    }