title: How do I prevent npm install from removing packages?
body: <p>I'm trying to set up a development environment with several packages, and as a result I need to manually install some dependencies.  More specifically, I have some local changes in several packages which I need to test before I can push them to github, so I can't just <code>npm install</code> the top level because it won't pick up those change.  So I run the first <code>npm install</code> manually on packages which are missing, and then try to run my node code and see which package it is still missing, then try to <code>npm install</code> what it says is missing.</p>
  
  <p>However, when I go to install the second package, it ends up with this message:</p>
  
  <pre><code>added 3 packages from 4 contributors, removed 799 packages and audited 3 packages in 4.197s
  </code></pre>
  
  <p>The second install removed practically <em>every</em> package that was already installed!  I didn't notice this until about the third time, when I realized that I seemed to be installing the same thing over and over.</p>
  
  <p>However can I prevent this particularly naughty behavior and force npm to <em>only install what I tell it to and leave everything else alone</em>?</p>