title: Merge two maps to resultant Map in Groovy
body: <p>I have two maps as:</p>
  
  <pre><code>firstMap = [totalProjectCount:53, activeProjectCount:29, completedProjectCount:1, userCount:85]
  secondMap = [totalProjectCount:48, activeProjectCount:41, completedProjectCount:0, userCount:123]
  </code></pre>
  
  <p>and i need result such as:</p>
  
  <pre><code>resultMap = [totalProjectCount:101, activeProjectCount:70, completedProjectCount:1, userCount:208]
  </code></pre>