// A With nullability  
abstract class AbstractResourceTopic private constructor(private val state: ResourceState?, private val isOn: Boolean?) {

        constructor(state: ResourceState) : this(state = state, isOn = null)
        constructor(isOn: Boolean) : this(state = null, isOn = isOn)
  }

// B with different types
  abstract class AbstractResourceTopic private constructor(private val resourceTopicType: ResourceTopicType) {

        constructor(state: Int) : this(ResourceTopicType.A(state))
        constructor(isOn: Boolean) : this(ResourceTopicType.B(isOn))

        sealed class ResourceTopicType{
            data class A(val state: ResourceState): ResourceTopicType()
            data class B(val isOn: Boolean): ResourceTopicType()
        }
	}
  }