title: What is the fastest way to generate a long random string in Go?
body: <p>Like [a-zA-Z0-9] string:</p>
  
  <p><em>na1dopW129T0anN28udaZ</em></p>
  
  <p>or hexadecimal string:</p>
  
  <p><em>8c6f78ac23b4a7b8c0182d</em></p>
  
  <p>By long I mean 2K and more characters.</p>