text: const view = url => {
      console.log(`Loading ${url}`);
  }
  	
  const errorHandler = error => {
      console.log(`The error is ${error}`);
  }
  	
  const download = (url, callback) => {
      console.log(`Downloading ${url}...`);
      callback();
  }
  	
  let url1 = "https://images.freeimages.com/images/large-previews/4ab/fruits-and-vegetables-1-1324165.jpg";
  let url2 = "https://images.freeimages.com/images/large-previews/d42/vegetables-4-1189021.jpg"
  let url3 = "https://images.freeimages.com/images/large-previews/360/banana-1-1330048.jpg"
  	
  download(url1, function() {
      setTimeout(() => {
      if(url1.length !== 0) {
          view(url1);
          download(url2, function() {
          setTimeout(() => {
          if(url2.length !== 0) {
                  view(url2);
                      download(url3, function() {
                      setTimeout(() => {
                          if(url3.length !== 0) {
                          view(url3);
                          } else {
                          errorHandler("URL is not provided");
                          }
                      }, 2000)
                      })
                  } else {
                  errorHandler("URL is not provided");
                  }
          }, 2000)
          })
      } else {
          errorHandler("URL is not provided");
          }
      }, 2000)
  });
      