public static <R, T> Function<T, R> spy1st(Function<T, R> function, Box<T> param) {
        return spy(function, Box.<R>empty(), param);
    }
public static < R , T > Function < T , R > spy1st ( Function < T , R > function , Box < T > param ) { return spy ( function , Box . < R > empty ( ) , param ) ; }
Proxies a function spying for parameter.

@param <R> the function result type
@param <T> the function parameter type
@param function the function that will be spied
@param param a box that will be containing spied parameter
@return the proxied function