code: function generateAuthorizationHeaderValue(signedHeaders, signKey, signingMsg) {
  		var signature = CryptoJS.HmacSHA256(signingMsg, signKey);
  		var authHeader = 'SNWS2 Credential=' +cred.token
  			+',SignedHeaders=' +signedHeaders.join(';')
  			+',Signature=' +CryptoJS.enc.Hex.stringify(signature);
  		return authHeader;
  	}
docs: Generate the V2 HTTP Authorization header.
  
  @param {String} token the SN token ID
  @param {Array} signedHeaders the sorted array of signed header names
  @param {Object} signKey the key to encrypt the signature with
  @param {String} signingMsg the message to sign
  @return {String} the HTTP header value
  @preserve