Get enum convert test passing, private API changed in 3.9

Author: cdleary

py_samples/int_enum_convert.py

@@ -0,0 +1,17 @@
+import enum
+from enum import IntEnum as _IntEnum
+
+FOO = 42
+BAR = 64
+smol = 128
+
+# This private interface changed at some point between 3.7 and 3.9.
+convert = _IntEnum._convert if hasattr(_IntEnum, '_convert') else _IntEnum._convert_
+
+converted = convert('Stuff', __name__,
+                    lambda name: name.isupper())
+assert converted.__name__ == 'Stuff', repr(converted)
+assert converted.FOO.value == 42
+assert converted.BAR.value == 64
+assert hasattr(converted, 'FOO')
+assert not hasattr(converted, 'smol')