title: Expand on this autoboxing explanation
body: <p>I asked:</p>
  
  <blockquote>
    <p>Is autoboxing/unboxing is done at runtime (JVM) or compile time (compiler)?</p>
  </blockquote>
  
  <p>I received this answer: </p>
  
  <blockquote>
    <p>Autoboxing is achieved by the insertion of method calls and casts by the compiler, into the code. These calls and casts are handled at runtime.</p>
  </blockquote>
  
  <p>Please explain in more detail.</p>