title: At which length is a String key of a HashMap considered bad-practice?
body: <p>I try to pay attention to good performance and clean code all the time. </p>
  
  <p>I'm having difficulties trying to grasp whether it's sane to have a HashMap with keys of 150 characters.</p>
  
  <ul>
  <li>Is there an unwritten law to the length of the HashMap key?</li>
  <li>Is it considered bad practice to have String keys of let's say 150 characters?</li>
  <li>Does it affect performance? At which length?</li>
  </ul>