add the sub command, which is often used when you want more detail configuration of sub command
the command used as the sub command
see also this.command(Args...)(string nameAndArgs, bool[string] cmdOpts = null) Args: see alos this.command(Args...)(string nameAndArgs, bool[string] cmdOpts = null)
Self for chain call
See Implementation
add the sub command, which is often used when you want more detail configuration of sub command