while input the same text as before ,lib while make application crash

[Nimeizi]

protected void appendInputTag(String tag) {
        final TagView previousInputTag = getInputTag();
        if (previousInputTag != null) {
            throw new IllegalStateException("Already has a INPUT tag in group.");//this exception
        }
        final TagView newInputTag = new TagView(getContext(), TagView.STATE_INPUT, tag);
        newInputTag.setOnClickListener(mInternalTagClickListener);
        addView(newInputTag);
    }