struct State {
  var isLoading: Bool
  var isSaveEnabled: Bool
  var name: String
}

let observable: Observable<State> = ...

let decision = testBehavior(of: observable) { dsl in 
  dsl.match { $0.isLoading == false }
  dsl.assert(.always) { $0.isLoading == false }
  dsl.match { $0.name == "Updated Name" }
  dsl.match { $0.isSaveEnabled == true }
  dsl.run(.async) { triggerSaving() }
  dsl.match { $0.isSaveEnabled == false }
}

// Decision will be
//  .correct: If no assertions failed and all match clauses matched
//  .failed: If any assetions failed or observable completes or times out without matching

  dsl.match { state in 
    predicate  
  }

  dsl.assert(.always) { state in
    assertion
  }

  dsl.assert(.untilNextMatch) { state in
    assertion
  }

  dsl.unordered {
    dsl...  // matchers/assertions or other scopes
  }

  dsl.first {
    dsl... // matchers/assertions or other scopes
  }