its side-effects (initialization), use the <a href="#Blank_identifier">blank</a>
identifier as explicit package name:
</p>

<pre>
import _ "lib/math"
</pre>


<h3 id="An_example_package">An example package</h3>

<p>
Here is a complete Go package that implements a concurrent prime sieve.
</p>

<pre>
package main

import "fmt"