title: Adding Python EntryPoints at runtime
body: <p>Starting by hypothesys that I have already defined and installed a package with and entrypoint that looks like:</p>
  
  <pre><code>setup(...
      entry_points={
          'group.subgrp': []
      }
  ...)
  </code></pre>
  
  <p>Then during runtime I would love to define some functions and attach them as entrypoints. The pseudo-code could looks like:</p>
  
  <pre><code>@Entrypoint.attach(group='group.subgrp', name='dummy_name')
  def my_dummy_function():
      ....
  </code></pre>
  
  <p>Is that doable?</p>
  
  <p>EDIT: After write the question, I have came to conclusion that this makes no sense, since the callable defined on entrypoints are 'accessible'  even if the package isn't being "ran". Anyway I will leave the question here, just to hear from community.</p>