Confusing parser warning

Hey all. Just to let you know I observed this same error just now when I mistakenly included an extra , in the function call.

E.g.

functions{     
 
  
  real fun_mre(real x, real y, real z ){ 
    return(x + y + z);
                      }          
  
  
  real fun_mre1( real x, real y, real z ){ 
       real total;
       total = fun_mre(x,
                        y,,
                        z); 
        return(total);
    }
  }
  data{}
  model{}