title: Is it possible to retroactively turn a set of commits into a branch?
body: <p>Say I have a git repository and I've been working on master, can I retroactively create a branch.  For example:</p>
  
  <p>A - B - C - A1 - D - A2 - E</p>
  
  <p>I want to make it look like this:</p>
  
  <pre><code>A - A1 - A2   
  \           \   
  B - C - D - E
  </code></pre>
  
  <p>The specific use case is when I've cherry-picked a bunch of commits into an old version branch and it needs to go into multiple older versions and I don't want to repeat the cherry-pick on all those revision.</p>
  
  <p>Essentially it's something that would have been good as a feature or topic branch in the first place but wasn't created like that.</p>