code: public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) {
          if (mv != null) {
              mv.visitLookupSwitchInsn(dflt, keys, labels);
          }
      }
docs: Visits a LOOKUPSWITCH instruction.
  
  @param dflt
  beginning of the default handler block.
  @param keys
  the values of the keys.
  @param labels
  beginnings of the handler blocks. <tt>labels[i]</tt> is the
  beginning of the handler block for the <tt>keys[i]</tt> key.