You can also remove context elements from a combined context if needed. To do this, you need to have a reference to the key of the element that you want to remove. For example, let's modify the previous example so that we separate the combined context:

fun main(args: Array<String>) = runBlocking {
    val dispatcher = newSingleThreadContext("myDispatcher")
    val handler = CoroutineExceptionHandler({ _, throwable ->
        println("Error captured")
        println("Message: ${throwable.message}")
    })

    // Combine two contexts together    
    val context = dispatcher + handler

    // Remove one element from the context
    val tmpCtx = context.minusKey(dispatcher.key)

    launch(tmpCtx) {
        println("Running in ${Thread.currentThread().name}")
        TODO("Not implemented!")
    }.join()
}

This will be the same as if we use launch(handler) {...}. Notice here that the thread corresponds to the default dispatcher instead of it being the thread of dispatcher: