title: How to make custom widget/component in flutter?
body: <p>Let say I want a container with this style -> rounded shape and with border.</p>
  
  <p>Should I create a theme for Container?
  Or should I create my custom widget/component?</p>
  
  <p>My main concern here is not to repeat everything so I'm thinking about this 2 possibilities.</p>
  
  <p>Which one more recommended?</p>
  
  <p>Kind Regards</p>
  
  <hr>
  
  <p>And why people down voted my question. I really don't know :(</p>