title: how to duplicate item on a map (not in the end)
body: <p>I want to duplicate an existing item on the map. I have a map of images, Let say I have [1,2,3] and I want to clone or duplicate 2 so I will get [1,2,2,3], how can I do that?</p>
  
  <p>I have images gallery. I have a 'clone button' that if you want to clone an image you will get the same image up next. 
  for example: (flower, car, cat, water) and than clone 'car' will get us (flower, car, car, cat, water).</p>
  
  <pre><code>//images- is the current map.
    // dto- is the item I am searching
    cloneImage(dto) {
      const { images } = this.state;
      let newImages = [];
      newImages = images.map((image) =&gt; {
        if (image.id === dto.id) {
          // this also didn't work- images.map(image).push(dto);
         return newImages.concat([image, image]);
        } else {
          return image;
        }
      });
      this.setState({
        images: newImages
      });
    }
  </code></pre>
  
  <p>So, I found my item in the map, but when I tried to duplicate I used concat but instead of clone the existing to [1,2,2,3] I got [1, [2,2] , 3].</p>