Note that using the module code object to find duplicates does not
allow for selecting among the different code types: function, nested
function, method or class.


Duplicates are extensively used within the std lib:

Running find_duplicate_test_names.py, the initial script from issue
16056, on the whole std lib instead of just Lib/test, after updating
the script to list all the duplicates (except <lambda>, <genexp>,
...) with:

    if not name[-1].startswith('<'):
        yield '.'.join(name)

prints 347 (on a total of 1368 std lib .py files) duplicate
functions, methods or classes.


To eliminate module level functions (but not nested functions), the
script is run now with the following change:

    if len(name) > 2 and not name[-1].startswith('<'):
        yield '.'.join(name)

and lists 188 duplicate nested functions, methods or classes.  In
this list there are 131 duplicates in .py files located in the
subdirectory of a "test" directory.