Entrypoint class yet to be implemented
programcharacter, name or path of the executable or command.
paramslist of parameters.
formform to render the instruction to (exec or shell)
Other instruction classes: Add-class,
Arg-class, Cmd-class,
Comment-class, Copy-class,
Env-class, Expose-class,
From-class,
Healthcheck-class,
Instruction-class,
Label-class,
Maintainer-class,
Onbuild-class, Run-class,
Run_shell-class, Shell-class,
Stopsignal-class,
Volume-class, Workdir-class
#no example yet