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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 POST(self, **kwargs):
        r'''
        Easily generate keys for a minion and auto-accept the new key

        Accepts all the same parameters as the :py:func:`key.gen_accept
        <salt.wheel.key.gen_accept>`.

        .. note:: A note about ``curl``
           Avoid using the ``-i`` flag or HTTP headers will be written and
           produce an invalid tar file.

        Example partial kickstart script to bootstrap a new minion:

        .. code-block:: text

            %post
            mkdir -p /etc/salt/pki/minion
            curl -sSk https://localhost:8000/keys \
                    -d mid=jerry \
                    -d username=kickstart \
                    -d password=kickstart \
                    -d eauth=pam \
                | tar -C /etc/salt/pki/minion -xf -

            mkdir -p /etc/salt/minion.d
            printf 'master: 10.0.0.5\nid: jerry' > /etc/salt/minion.d/id.conf
            %end

        .. http:post:: /keys

            Generate a public and private key and return both as a tarball

            Authentication credentials must be passed in the request.

            :status 200: |200|
            :status 401: |401|
            :status 406: |406|

        **Example request:**

        .. code-block:: bash

            curl -sSk https://localhost:8000/keys \
                    -d mid=jerry \
                    -d username=kickstart \
                    -d password=kickstart \
                    -d eauth=pam \
                    -o jerry-salt-keys.tar

        .. code-block:: text

            POST /keys HTTP/1.1
            Host: localhost:8000

        **Example response:**

        .. code-block:: text

            HTTP/1.1 200 OK
            Content-Length: 10240
            Content-Disposition: attachment; filename="saltkeys-jerry.tar"
            Content-Type: application/x-tar

            jerry.pub0000644000000000000000000000070300000000000010730 0ustar  00000000000000
        '''
        lowstate = cherrypy.request.lowstate
        lowstate[0].update({
            'client': 'wheel',
            'fun': 'key.gen_accept',
        })

        if 'mid' in lowstate[0]:
            lowstate[0]['id_'] = lowstate[0].pop('mid')

        result = self.exec_lowstate()
        ret = next(result, {}).get('data', {}).get('return', {})

        pub_key = ret.get('pub', '')
        pub_key_file = tarfile.TarInfo('minion.pub')
        pub_key_file.size = len(pub_key)

        priv_key = ret.get('priv', '')
        priv_key_file = tarfile.TarInfo('minion.pem')
        priv_key_file.size = len(priv_key)

        fileobj = BytesIO()
        tarball = tarfile.open(fileobj=fileobj, mode='w')

        if six.PY3:
            pub_key = pub_key.encode(__salt_system_encoding__)
            priv_key = priv_key.encode(__salt_system_encoding__)

        tarball.addfile(pub_key_file, BytesIO(pub_key))
        tarball.addfile(priv_key_file, BytesIO(priv_key))
        tarball.close()

        headers = cherrypy.response.headers
        headers['Content-Disposition'] = 'attachment; filename="saltkeys-{0}.tar"'.format(lowstate[0]['id_'])
        headers['Content-Type'] = 'application/x-tar'
        headers['Content-Length'] = len(fileobj.getvalue())
        headers['Cache-Control'] = 'no-cache'

        fileobj.seek(0)
        return fileobj