title: What does `__import__('pkg_resources').declare_namespace(__name__)` do?
body: <p>In some <code>__init__.py</code> files of modules I saw such single line:</p>
  
  <pre><code>__import__('pkg_resources').declare_namespace(__name__)
  </code></pre>
  
  <p>What does it do and why people use it? Suppose it's related to dynamic importing and creating namespace at runtime.</p>