'Disable ``phase`` from execution.
:param string phase: Name of ``phase``
:raises ValueError: *phase* could not be found.'

def disable_phase(self, phase):

    if (phase not in task_phases):
        raise ValueError((u'%s    is    not    a    valid    phase' % phase))
    if (phase not in self.disabled_phases):
        log.debug((u'Disabling    %s    phase' % phase))
        self.disabled_phases.append(phase)
