make_command: Helper function to create new command.
Description
make_command
is a helper function used by developers to create function for
a new Command
object. It should not be used by end users.
Usage
make_command(name, fun, envir = caller_env())
Arguments
- name
A string of the function name.
- fun
A function used to initialize the Command
object.
- envir
A environment used to bind the created function.