Install dbus-tests by entering the following commands in the terminal:
sudo apt update sudo apt install dbus-tests
simple interprocess messaging system (test infrastructure)
D-Bus is a message bus, used for sending messages between applications. Conceptually, it fits somewhere in between raw sockets and CORBA in terms of complexity. . This package provides automated and manual tests for D-Bus, and the dbus-test-tool utility. It also provides copies of the D-Bus libraries and executables compiled with extra debug information and logging. . See the dbus package description for more information about D-Bus in general.