gistfile1.txt

          // 1. Must only say "ClientError::*" ONCE.
          // 2. Must return Result<Vec<String>, ClientError::*>             
          // 3. No nesting blocks or nested closures                      
          // 4. Can be no unwrap, or try macro
          //use std::ops::Deref;
          let services = document 
              .select("ul.info") 
              .ok() 
              .and_then( |mut select| select.nth(1) ) 
              .as_ref() 
              .map( |ndr| ndr.as_node() ) 
              .and_then( |dn| dn.select("li").ok() ) 
              .map( |e| e.map( |e| e.text_contents() ).collect::<Vec<String>>() ) 
              .ok_or(ClientError::DownloadFailed(listing_url.to_owned()))?;