To run the examples from this chapter, you should install the kotlinx-coroutines-core library. If you use the Gradle build tool, you will have to add the following line to the dependency section of the build.gradle file:
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:0.23.0'
You can find the examples from this chapter on GitHub at the following link: https://github.com/PacktPublishing/Hands-On-Object-Oriented-Programming-with-Kotlin/tree/master/src/main/kotlin/Chapter07.