title: Does initializing a variable in the init function of a package ensures a single instance in a golang app?
body: <p>I am writing a Bloom Filter package.
  Within my package, I want to create an instance of <code>X</code> (non-exported) which I want to exist only as a single instance; no matter how many times my package is imported into an app. </p>
  
  <p>A simple snippet of what I am doing is:</p>
  
  <pre><code>package superduperbloomfilter
  
  var x X
  
  func init() {
      x = X.New(....)
  }
  </code></pre>
  
  <p>Is this correct ?</p>