expect_tuner = function(tuner) {
  expect_r6(tuner, "Tuner", public = c("optimize", "param_set"), private = ".optimize")
  expect_class(tuner$param_set, "ParamSet")
  expect_function(tuner$optimize, args = "inst")
}

expect_terminator = function(term) {
  expect_r6(term, "Terminator", public = c("is_terminated", "param_set"))
  expect_class(term$param_set, "ParamSet")
}
