title: Go StartsWith(str string)
body: <p>Is there a <code>StartsWith(str1, str2 string)</code> function that can check if <code>str1</code> is a prefix of <code>str2</code> in Go language?</p>
  
  <p>I want a function similar to the <a href="http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/String.html#startsWith(java.lang.String)" rel="noreferrer">Java's <code>startsWith()</code></a>.</p>