Scrapper Function Not Working

Screen Link:

My Code: <!–

scraper <- function(url,selector,output = "text", all_nodes = TRUE) {
  
content<- read_html(url)

if(all_nodes){
all_nodes <- html_nodes
} else { all_nodes <- html_node }
  
  
 if(output == "text"){
   
   output <- html_text()
 }else if (output == "table"){
   output <- html_table()
 }else if (output == "attrs"){
   output <- html_attrs()
 }else{output <- html_attr()
 
 }
 
scrape <- content %>% all_nodes(selector) %>% output
  scrape
   
}


```-->

Replace this line with your code


What I expected to happen:
I expect this 

scraper(url = "http://dataquestio.github.io/web-scraping-pages/2014_super_bowl.html", 
        selector = "table tr:nth-child(3) td")
to work

What actually happened:


Error in xml2::xml_text(x, trim = trim) : argument "x" is missing, with no default