func remove(word: String) -> Bool {
        var deleteWord = Array(word)
        var nodes = getNodesList(word: word)
        guard nodes != nil else {return false}
        var wordIndex = deleteWord.count - 1
        for nodeIdx in (1..<nodes!.count - 1 ).reversed() {
            if ( nodes![nodeIdx].children[ deleteWord[wordIndex] ]!.children.count < 1 ) {
                 nodes![nodeIdx].children[ deleteWord[wordIndex] ] = nil
            }
            wordIndex -= 1
        }
        return true
    }