title: How do I query artifactory for artifacts that are missing a property
body: <p>I have a process I want to run to add some arbitrary property to artifacts that meet a certain criteria but do not already have the property assigned. I tried querying like:</p>
  
  <pre><code>items.find({
    "$and":[
      {"repo": "libs-release-local"},
      {"@foo": {"$eq":null}}
    ]
  
  }).include("path", "name")
  </code></pre>
  
  <p>but that never returns any results. Is there some way to query for items that do not have a "foo" property?</p>