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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 silence(warning, silence=True):
    ''' Silence a particular warning on all Bokeh models.

    Args:
        warning (Warning) : Bokeh warning to silence
        silence (bool) : Whether or not to silence the warning

    Returns:
        A set containing the all silenced warnings

    This function adds or removes warnings from a set of silencers which
    is referred to when running ``check_integrity``. If a warning
    is added to the silencers - then it will never be raised.

    .. code-block:: python

        >>> from bokeh.core.validation.warnings import EMPTY_LAYOUT
        >>> bokeh.core.validation.silence(EMPTY_LAYOUT, True)
        {1002}

    To turn a warning back on use the same method but with the silence
    argument set to false

    .. code-block:: python

        >>> bokeh.core.validation.silence(EMPTY_LAYOUT, False)
        set()

    '''
    if not isinstance(warning, int):
        raise ValueError('Input to silence should be a warning object '
                         '- not of type {}'.format(type(warning)))
    if silence:
        __silencers__.add(warning)
    elif warning in __silencers__:
        __silencers__.remove(warning)
    return __silencers__