In the previous chapter, we learned about operators and how to use them. We learned how operators can help us in solving complex problems with ease. We got a grip on operators and their types, and we learned basic filtering operators and transforming operators in detail. It's time to move on to some interesting and advanced things you can do with operators.

We will cover the following topics in this chapter:

• Combining producers (Observable/Flowable)
• Grouping emissions
• Filtering/suppressing operators
• Error handling operators
• Real-world HTTP client example

So, what are we waiting for? Let's get started with combining producer (Observable/Flowable) instances.