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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _clear_namespace():
 """ Clear names that are not part of the strict ES API """

    ok_names = set(default_backend.__dict__)
    ok_names.update(['gl2', 'glplus'])  # don't remove the module
    NS = globals()
    for name in list(NS.keys()):
        if name.lower().startswith('gl'):
            if name not in ok_names:
                del NS[name]