code: function getTokensLength(tokens) {
    if (typeof tokens === 'string') {
      return tokens.length;
    }
    return tokens.reduce((acc, token) => {
      return acc + (token.length ? token.length : 0);
    }, 0);
  }
docs: getTokensLength - Function calculate tokens' length
  
  @param tokens
  @returns {Number}