public UnsafeRefToNativeHeadRemovableList(NativeHeadRemovableList <T> list)
 {
     _list  = new UnsafeRefToNativeList <T>(list._list);
     _start = list._start.Target;
 }
 internal static UnsafeRefToNativeHeadRemovableList <T> GetUnsafeRef <T>(this NativeHeadRemovableList <T> target)
     where T : unmanaged
 {
     return(new UnsafeRefToNativeHeadRemovableList <T>(target));
 }