can't use Unicode in C# with cb65

I am using r4unicode field type from C#. As I can see, table is
created correctly. Then I suppose I have to use assignUnicode()
function to put unicode string to this field. But how to read value
back from field to C# string - something like GetUniconde() doesn't
exist. According to do***entation I could use Field4::bytes function
to read it as byte array (at least), but that function doesn't exist
in Field4 class in my version of CodeBase.