I am trying to retrieve a function object from a call object
In this example

```
ff = function(x) {gg(x)}     
gg = function(y) {uu(y)}     
uu = function(z) {browser()} 
ff(1)                        

```

Say I want to get the function `ff` from `sys.calls()[[1]]` I got the below but I want the `ff` function object, how can I get it

```
Browse[1]> deparse(sys.calls()[[1]][1])
[1] "ff()"                             

```