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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 refresh_db(jail=None, chroot=None, root=None, force=False, **kwargs):
    '''
    Refresh PACKAGESITE contents

    .. note::

        This function can accessed using ``pkg.update`` in addition to
        ``pkg.refresh_db``, to more closely match the CLI usage of ``pkg(8)``.

    CLI Example:

    .. code-block:: bash

        salt '*' pkg.refresh_db

    jail
        Refresh the pkg database within the specified jail

    chroot
        Refresh the pkg database within the specified chroot (ignored if
        ``jail`` is specified)

    root
        Refresh the pkg database within the specified root (ignored if
        ``jail`` is specified)

    force
        Force a full download of the repository catalog without regard to the
        respective ages of the local and remote copies of the catalog.

        CLI Example:

        .. code-block:: bash

            salt '*' pkg.refresh_db force=True
    '''
    # Remove rtag file to keep multiple refreshes from happening in pkg states
    salt.utils.pkg.clear_rtag(__opts__)
    cmd = _pkg(jail, chroot, root)
    cmd.append('update')
    if force:
        cmd.append('-f')
    return __salt__['cmd.retcode'](cmd, python_shell=False) == 0