code: function Token (token, clientId) {
    this.token = token;
    this.clientId = clientId;
  
    if (token) {
      try {
        const parts = token.split('.');
        this.header = JSON.parse(Buffer.from(parts[0], 'base64').toString());
        this.content = JSON.parse(Buffer.from(parts[1], 'base64').toString());
        this.signature = Buffer.from(parts[2], 'base64');
        this.signed = parts[0] + '.' + parts[1];
      } catch (err) {
        this.content = {
          exp: 0
        };
      }
    }
  }
docs: Construct a token.
  
  Based on a JSON Web Token string, construct a token object. Optionally
  if a `clientId` is provided, the token may be tested for roles with
  `hasRole()`.
  
  @constructor
  
  @param {String} token The JSON Web Token formatted token string.
  @param {String} clientId Optional clientId if this is an `access_token`.