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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 initialize_extensions(shell, extensions):
 """ Partial copy of `InteractiveShellApp.init_extensions` from IPython. """

    try:
        iter(extensions)
    except TypeError:
        pass  # no extensions found
    else:
        for ext in extensions:
            try:
                shell.extension_manager.load_extension(ext)
            except:
                ipy_utils.warn.warn(
                    "Error in loading extension: %s" % ext +
                    "\nCheck your config files in %s" % ipy_utils.path.get_ipython_dir())
                shell.showtraceback()