docs: @Override
      public void sawOpcode(int seen) {
          if (seen != Const.INVOKESPECIAL) {
              sawOpenInAppendMode = false;
              return;
          }
          String calledClassName = getClassConstantOperand();
          String calledMethodName = getNameConstantOperand();
          String calledMethodSig = getSigConstantOperand();
          if (!sawOpenInAppendMode) {
              if ("java/io/ObjectOutputStream".equals(calledClassName) && Const.CONSTRUCTOR_NAME.equals(calledMethodName)
                      && "(Ljava/io/OutputStream;)V".equals(calledMethodSig)
                      && stack.getStackItem(0).getSpecialKind() == OpcodeStack.Item.FILE_OPENED_IN_APPEND_MODE) {
                  bugReporter.reportBug(new BugInstance(this, "IO_APPENDING_TO_OBJECT_OUTPUT_STREAM", Priorities.HIGH_PRIORITY)
                  .addClassAndMethod(this).addSourceLine(this));
              }
              return;
          }
          if ("java/io/FileOutputStream".equals(calledClassName) && Const.CONSTRUCTOR_NAME.equals(calledMethodName)
                  && ("(Ljava/io/File;Z)V".equals(calledMethodSig) || "(Ljava/lang/String;Z)V".equals(calledMethodSig))) {
              OpcodeStack.Item item = stack.getStackItem(0);
              Object value = item.getConstant();
              sawOpenInAppendMode = value instanceof Integer && ((Integer) value).intValue() == 1;
          } else if ("java/io/BufferedOutputStream".equals(calledClassName) && Const.CONSTRUCTOR_NAME.equals(calledMethodName)
                  && "(Ljava/io/OutputStream;)V".equals(calledMethodSig)) {
              // do nothing
  
          } else if ("java/io/ObjectOutputStream".equals(calledClassName) && Const.CONSTRUCTOR_NAME.equals(calledMethodName)
                  && "(Ljava/io/OutputStream;)V".equals(calledMethodSig)) {
              bugReporter.reportBug(new BugInstance(this, "IO_APPENDING_TO_OBJECT_OUTPUT_STREAM", Priorities.HIGH_PRIORITY)
                  .addClassAndMethod(this).addSourceLine(this));
              sawOpenInAppendMode = false;
          } else {
              sawOpenInAppendMode = false;
          }
  
      }