fn value_of(&self, arg_name: &'static str) -> Option<&Value> {
        self.args.get(arg_name).and_then(|argument| {
            argument
                .user_value
                .as_ref()
                .or_else(|| argument.default_value.as_ref())
        })
    }
/// Get the value for the argument specified by `arg_name`.
Get the value for the argument specified by `arg_name`.
Get the value for the argument specified by ` arg_name ` .
fn value_of(&self, arg_name: &'static str) -> Option<&Value> {
        self.args.get(arg_name).and_then(|argument| {
            argument
                .user_value
                .as_ref()
                .or_else(|| argument.default_value.as_ref())
        })
    }
fn value_of ( & self , arg_name : & ' static str ) -> Option < & Value > { self . args . get ( arg_name ) . and_then ( | argument | { argument . user_value . as_ref ( ) . or_else ( | | argument . default_value . as_ref ( ) ) } ) }
Get the value for the argument specified by `arg_name`.
Get the value for the argument specified by ` arg_name ` .
&self
arg_name
&'static str
&self
arg_name
&'static str