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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 unset_role(username, role, **kwargs):
    '''
    Remove role from username.

    username
        Username for role removal

    role
        Role to remove

    no_save_config
        If True, don't save configuration commands to startup configuration.
        If False, save configuration to startup configuration.
        Default: False

    .. code-block:: bash

        salt '*' nxos.cmd unset_role username=daniel role=vdc-admin
    '''
    role_line = 'no username {0} role {1}'.format(username, role)
    return config(role_line, **kwargs)