title: Invisible java bytecode lines
body: <p>I am wondering why the line numbers of Java Bytecode are not consecutive.</p>
  
  <p>What happens for example in the (not listed) lines 2 and 3 of the following getter?</p>
  
  <pre><code>public java.lang.String getX();
  
  Code:
  0:   aload_0
  1:   getfield        #2; //Field x:Ljava/lang/String;
  4:   areturn
  </code></pre>
  
  <p>I'm using the ASM framework to work on bytecode. When visiting the code of a method using the tree API I get these "hidden" instructions as well (however with opcode -1). I would like to know what they are for.</p>