DivKit
· DivKit is an open source Server-Driven UI (SDUI) framework. SDUI is a an emerging technique that leverage the server to build the user interfaces of their mobile app.
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window div-size-provider-27.3.0.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.