'Override the L{reactors.getPlugins} function, normally bound to
L{twisted.plugin.getPlugins}, in order to control which
L{IReactorInstaller} plugins are seen as available.
C{self.pluginResults} can be customized and will be used as the
result of calls to C{reactors.getPlugins}.'

def setUp(self):

    self.pluginCalls = []
    self.pluginResults = []
    self.originalFunction = reactors.getPlugins
    reactors.getPlugins = self._getPlugins
