title: Namespaces in Imports field not imported from: All declared Imports should be used
body: <p>I am working on my R package. I am getting this error:</p>
  
  <pre><code>Namespaces in Imports field not imported from:
     ‘kableExtra’ ‘ranger’
    All declared Imports should be used.
  </code></pre>
  
  <p>I get this error with <code>devtools::check_rhub()</code> i.e. on linux and windows platform. When I check my package locally (mac os) with  <code>devtools::check()</code> all checks gets passed successfully.</p>
  
  <p>I looked deeper into the imports of my description file, currently I am doing:</p>
  
  <pre><code>Imports:  
      ranger(&gt;= 0.10.1),
      Metrics(&gt;= 0.1.3),
      kableExtra(&gt;= 0.9.0)
  </code></pre>
  
  <p>I am using functions from <code>ranger</code> and <code>kableExtra</code> using <code>::</code> like <code>ranger::function_name</code>, <code>kableExtra::function_name</code> since there are just one or two functions I need. </p>
  
  <p>I am not doing <code>importFrom</code> in Namespace file. Because, like I said, there are just 1 or 2 functions I need to borrow.</p>
  
  <p>Why am I getting this error ? What am I missing ? </p>