Correction for the fix for Bug 3508 - Persistent storage support breaks Linux compatibility.
A 2nd `make install' will fail attempting to create symlink libnvmemmory.so already created by 1st install.
Install should pre-emptively delete it.
# Used by test_doctest.py.
class TwoNames:
'''f() and g() are two names for the same method'''
def f(self):
'''
>>> print TwoNames().f()
f
'''
return 'f'
g = f # define an alias for f