Capability passing and dependency injection are just convoluted ways to describe passing parameters instead of using globals.
Capability passing is just extending that to the level of imports. Your files do not import the global I/O library and then use io.print(). They are passed a I/O library as the parameter {io} which defines a print() function and then call io.print().
Capability passing is just extending that to the level of imports. Your files do not import the global I/O library and then use io.print(). They are passed a I/O library as the parameter {io} which defines a print() function and then call io.print().