constructor(config) {
        this.content = config.content;
        this.id = config.id;
        this.single_word = config.single_word ?? false;
        this.lstrip = config.lstrip ?? false;
        this.rstrip = config.rstrip ?? false;
        this.special = config.special ?? false;
        this.normalized = config.normalized ?? null;
    }
Creates a new instance of AddedToken.
@param {Object} config Added token configuration object.
@param {string} config.content The content of the added token.
@param {number} config.id The id of the added token.
@param {boolean} [config.single_word=false] Whether this token must be a single word or can break words.
@param {boolean} [config.lstrip=false] Whether this token should strip whitespaces on its left.
@param {boolean} [config.rstrip=false] Whether this token should strip whitespaces on its right.
@param {boolean} [config.normalized=false] Whether this token should be normalized.
@param {boolean} [config.special=false] Whether this token is special.