code: public static InsnList loadArrayLength(InsnList arrayRef) {
          Validate.notNull(arrayRef);
          
          InsnList ret = new InsnList();
          ret.add(arrayRef);
          ret.add(new InsnNode(Opcodes.ARRAYLENGTH));
          
          return ret;
      }
docs: Gets the size of an array and puts it on to the stack.
  @param arrayRef instructions to get the array -- must leave an array on the stack
  @return instructions to get the size of the array -- will size an int on the stack
  @throws NullPointerException if any argument is {@code null}