title: How can I detect how many levels down Pry has gone
body: <p>If I'm at a Bash prompt and I type <code>bash</code> I can then detect that I'm at the 2nd level by typing <code>echo $SHLVL</code>.</p>
  
  <p>Suppose I'm in a pry session and I type <code>pry</code> again.  How can I detect that I'm at the 2nd level down? How can I detect the Pry level? Nothing listed in <code>(Pry.methods - Object.methods).sort</code>  seems to have anything useful.</p>
  
  <p>This is for testing some code for a pry-related project, where I need detect the level.</p>