ClojureScript:cljs.user> (def sb (goog.string.StringBuffer. "a"))
#<a>
ClojureScript:cljs.user> (. sb (append "a"))
#<aa>
ClojureScript:cljs.user> (.append sb "a")
#<aaa>
ClojureScript:cljs.user> (def f (.append sb))
#<
function (a1, opt_a2, var_args) {
    this.buffer_ += a1;
    if (opt_a2 != null) {
        for (var i = 1; i < arguments.length; i++) {
            this.buffer_ += arguments[i];
        }
    }
    return this;
}
>
ClojureScript:cljs.user> (fn? f)
true
ClojureScript:cljs.user> (f "a")
#<[object Object]>
ClojureScript:cljs.user> sb
#<aaa>