title: How to filter a Mutable Map in place in Kotlin
body: <p>I would like to remove items from a <code>MutableMap</code>, similar to <code>filter</code>.<br>
  In list I can use <code>removeAll { }</code> and <code>retainAll { }</code><br>
  (see this question: <a href="https://stackoverflow.com/questions/44674532/how-to-filter-a-list-in-place-with-kotlin">How to filter a list in-place with Kotlin?</a>).   </p>
  
  <p>Is there something similar for Mutable Maps?</p>
  
  <p>EDIT:</p>
  
  <p>I found that <code>entries</code> property of Map has those methods.</p>