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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 freeze_extensions(self):
 """Freeze the set of extensions into a single file. Freezing extensions can speed up the extension loading process on machines with slow file systems since it requires only a single file to store all of the extensions. Calling this method will save a file into the current virtual environment that stores a list of all currently found extensions that have been installed as entry_points. Future calls to `load_extensions` will only search the one single file containing frozen extensions rather than enumerating all installed distributions. """


        output_path = os.path.join(_registry_folder(), 'frozen_extensions.json')

        with open(output_path, "w") as outfile:
            json.dump(self._dump_extensions(), outfile)