title: Covering code in main function with unit tests
body: <p>Golang show that I have only 50% of covering code, and as I see code in main is not covered, I've tried to search but not found anything with explanations how to cover code in main.</p>
  
  <p><strong>main.go</strong></p>
  
  <pre><code>package main
  
  func Sum(x int, y int) int {
      return x + y
  }
  
  func main() {
      Sum(5, 5)
  }
  </code></pre>
  
  <p><strong>main_test.go</strong></p>
  
  <pre><code>package main
  
  import (
      "testing"
  )
  
  func TestSum(t *testing.T) {
      total := Sum(5, 5)
      if total != 10 {
          t.Fail()
      }
  }
  </code></pre>