Change more tests to use import_module for the modules that
should cause tests to be skipped.  Also rename import_function
to the more descriptive get_attribute and add a docstring.
diff --git a/Lib/test/test_startfile.py b/Lib/test/test_startfile.py
index 23e2708..8eeae72 100644
--- a/Lib/test/test_startfile.py
+++ b/Lib/test/test_startfile.py
@@ -12,7 +12,7 @@
 import os
 from os import path
 
-startfile = test_support.import_function(os, 'startfile')
+startfile = test_support.get_attribute(os, 'startfile')
 
 
 class TestCase(unittest.TestCase):