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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 gen_accept(id_, keysize=2048, force=False):
    r'''
    Generate a key pair then accept the public key. This function returns the
    key pair in a dict, only the public key is preserved on the master. Returns
    a dictionary.

    id\_
        The name of the minion for which to generate a key pair.

    keysize
        The size of the key pair to generate. The size must be ``2048``, which
        is the default, or greater. If set to a value less than ``2048``, the
        key size will be rounded up to ``2048``.

    force
        If a public key has already been accepted for the given minion on the
        master, then the gen_accept function will return an empty dictionary
        and not create a new key. This is the default behavior. If ``force``
        is set to ``True``, then the minion's previously accepted key will be
        overwritten.

    .. code-block:: python

        >>> wheel.cmd('key.gen_accept', ['foo'])
        {'pub': '-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBC
        ...
        BBPfamX9gGPQTpN9e8HwcZjXQnmg8OrcUl10WHw09SDWLOlnW+ueTWugEQpPt\niQIDAQAB\n
        -----END PUBLIC KEY-----',
        'priv': '-----BEGIN RSA PRIVATE KEY-----\nMIIEpAIBAAKCAQEA42Kf+w9XeZWgguzv
        ...
        QH3/W74X1+WTBlx4R2KGLYBiH+bCCFEQ/Zvcu4Xp4bIOPtRKozEQ==\n
        -----END RSA PRIVATE KEY-----'}

    We can now see that the ``foo`` minion's key has been accepted by the master:

    .. code-block:: python

        >>> wheel.cmd('key.list', ['accepted'])
        {'minions': ['foo', 'minion1', 'minion2', 'minion3']}
    '''
    id_ = clean.id(id_)
    ret = gen(id_, keysize)
    acc_path = os.path.join(__opts__['pki_dir'], 'minions', id_)
    if os.path.isfile(acc_path) and not force:
        return {}
    with salt.utils.files.fopen(acc_path, 'w+') as fp_:
        fp_.write(salt.utils.stringutils.to_str(ret['pub']))
    return ret