private void AddCompositePrimaryKey()
{
var keys = string.Join(", ",
_table.Columns
.Where(x => x.IsPrimaryKey)
//primary keys must be scalar so if it's a foreign key use the Id mirror property
//.Select(x => "x." + x.NetName + (x.IsForeignKey ? "Id" : string.Empty))
.Select(x => "x." + ClassWriter.PropertyName(x))
.ToArray());
_cb.AppendLine("// Primary key (composite)");
//double braces for a format
_cb.AppendFormat(Builder + "HasKey(x => new {{ {0} }});", keys);
}