patch 7.4.1769
Problem:    No "closed", "errors" and "encoding" attribute on Python output.
Solution:   Add attributes and more tests. (Roland Puntaier, closes #622)
diff --git a/src/if_py_both.h b/src/if_py_both.h
index de3e868..a0385f9 100644
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -503,6 +503,7 @@
     {"readable",    (PyCFunction)AlwaysFalse,		METH_NOARGS,	""},
     {"seekable",    (PyCFunction)AlwaysFalse,		METH_NOARGS,	""},
     {"writable",    (PyCFunction)AlwaysTrue,		METH_NOARGS,	""},
+    {"closed",      (PyCFunction)AlwaysFalse,		METH_NOARGS,	""},
     {"__dir__",	    (PyCFunction)OutputDir,		METH_NOARGS,	""},
     { NULL,	    NULL,				0,		NULL}
 };