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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 gunzip(gzipfile, template=None, runas=None, options=None):
    '''
    Uses the gunzip command to unpack gzip files

    template : None
        Can be set to 'jinja' or another supported template engine to render
        the command arguments before execution:

        .. code-block:: bash

            salt '*' archive.gunzip template=jinja /tmp/{{grains.id}}.txt.gz

    runas : None
        The user with which to run the gzip command line

    options : None
        Pass any additional arguments to gzip

        .. versionadded:: 2016.3.4

    CLI Example:

    .. code-block:: bash

        # Create /tmp/sourcefile.txt
        salt '*' archive.gunzip /tmp/sourcefile.txt.gz
        salt '*' archive.gunzip /tmp/sourcefile.txt options='--verbose'
    '''
    cmd = ['gunzip']
    if options:
        cmd.append(options)
    cmd.append('{0}'.format(gzipfile))

    return __salt__['cmd.run'](cmd,
                               template=template,
                               runas=runas,
                               python_shell=False).splitlines()