title: Read and write (edit) part of a json file in dart
body: <p>I use a JSON file in my application and it has a lot of data in it!</p>
  <p>When I wanna edit an element in that JSON I read the whole of it and save it in a runtime map variable and after editing it I clean the previous file and rewrite new data.</p>
  <p>The question is &quot;Is there any way to edit that file without reading and writing the whole of it?&quot;</p>
  <p>I know there is a method called <code>openRead</code> but I'm not sure it helps for JSON data.</p>
  <p>Thanks in advance.</p>