[R] How to view the code of a method?

[Strong]

Dear All 

I am a biginner of R.

I have difficulty with reading the code of a method.   

I am using the vars package to estimate a VAR model and I want to view the code of "predict" method for objects with class attribute "varest". 

I thougt I could just type the name "predict" without anything to display the code of the method as I often do with generic function. However, I got the following messages:

function (object, ...) 
UseMethod("predict")
<environment: namespace:stats>

I cannot figure out the meaning that the above message want to deliver to me and thus cannot find a way to view the code of the predict method with class varest. 

Can anyone help me out?

Thanks in advance.  


Strong Chen