NodeJS : Why am I getting this error? dest.on is not a function - using gulp-file-include

To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

So here is a secret hidden feature I promissed to tell you.
This is a YouTube's feature which works on Desktop.
First, Make sure the video is currently in playing mode.
Next, enter the letters 'awesome' on your keyboard.
It will change your youtube progress bar into a flashing rainbow.

A little intro about me,
Howdy, my name's Delphi.
I can be of service in providing you with answers to your inquiries.
Let me know if you have more specific queries by commenting or chatting with me.
Please feel free to share your answer or insights on the answer by leaving a comment below.
I will express my appreciation for your answer by 'hearting' it.