title: Can anyone help me understand what is the use of .spread in Bluebird library
body: <p>I'm working on my first Nodejs application, someone else has developed this application before me and I'm trying to fix some issue and having trouble understanding the following.</p>
  
  <pre><code>return Promise.join(
          findStagingAdvanced(stagingQuery),
          findDboAdvanced(dboQuery)
      )     
      .spread((stagingIssues, dboIssues) =&gt; _.concat(dboIssues, stagingIssues))
      .then(....) 
  </code></pre>