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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 import_preferred_memcache_lib(self, servers):
 """Returns an initialized memcache client. Used by the constructor."""

        try:
            import pylibmc
        except ImportError:
            pass
        else:
            return pylibmc.Client(servers)

        try:
            from google.appengine.api import memcache
        except ImportError:
            pass
        else:
            return memcache.Client()

        try:
            import memcache
        except ImportError:
            pass
        else:
            return memcache.Client(servers)