def METHOD_NAME(self, use_interpolation):
    c = {}
    from buildbot.config import BuilderConfig
    from buildbot.plugins import schedulers
    from buildbot.plugins import steps
    from buildbot.plugins import util
    from buildbot.process.factory import BuildFactory
    fake_reporter = FakeSecretReporter('http://example.com/hook',
                                       auth=('user', Interpolate('%(secret:httppasswd)s')))
    c['services'] = [fake_reporter]
    c['schedulers'] = [
        schedulers.ForceScheduler(
            name="force",
            builderNames=["testy"])]
    c['secretsProviders'] = [FakeSecretStorage(secretdict={"foo": "secretvalue",
                                                           "something": "more",
                                                           'httppasswd': 'myhttppasswd'})]
    f = BuildFactory()
    if use_interpolation:
        if os.name == "posix":
            # on posix we can also check whether the password was passed to the command
            command = Interpolate('echo %(secret:foo)s | ' +
                                  'sed "s/secretvalue/The password was there/"')
        else:
            command = Interpolate('echo %(secret:foo)s')
    else:
        command = ['echo', util.Secret('foo')]
    f.addStep(steps.ShellCommand(command=command))
    c['builders'] = [
        BuilderConfig(name="testy",
                      workernames=["local1"],
                      factory=f)]
    yield self.setup_master(c)
    return fake_reporter