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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 stp(br=None, state='disable', iface=None):
    '''
    Sets Spanning Tree Protocol state for a bridge

    CLI Example:

    .. code-block:: bash

        salt '*' bridge.stp br0 enable
        salt '*' bridge.stp br0 disable

    For BSD-like operating systems, it is required to add the interface on
    which to enable the STP.

    CLI Example:

    .. code-block:: bash

        salt '*' bridge.stp bridge0 enable fxp0
        salt '*' bridge.stp bridge0 disable fxp0
    '''
    kernel = __grains__['kernel']
    if kernel == 'Linux':
        states = {'enable': 'on', 'disable': 'off'}
        return _os_dispatch('stp', br, states[state])
    elif kernel in SUPPORTED_BSD_LIKE:
        states = {'enable': 'stp', 'disable': '-stp'}
        return _os_dispatch('stp', br, states[state], iface)
    else:
        return False