unrecognized selector sent to instance (ViewController)

I adapted some code from a YT tutorial but the code doesn't seem to work (Xcode 10.1, Swift 4.2):

//

class ViewController: UIViewController, UITextViewDelegate {

    
    @IBOutlet weak var myTextView: UITextView!
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        // Make current 
//  ViewController.swift
//  DGTest
//
//  Created by me on 15.01.19.
//  
//

import UIKit
ViewController respond to UITextViewDelegate events
        myTextView.delegate = self
        
        // Update UITextView content
        myTextView.text = "Some preset text..\ntap in view and then outside view.."
        
        // Change UITextView background colour
        myTextView.backgroundColor = UIColor.yellow
        
        // User RGB colour
        myTextView.backgroundColor = UIColor(red: 39/255, green: 53/255, blue: 182/255, alpha: 1)
        
        // Update UITextView font size and colour
        myTextView.font = UIFont.systemFont(ofSize: 20)
        myTextView.textColor = UIColor.white
        
        myTextView.font = UIFont.boldSystemFont(ofSize: 20)
        myTextView.font = UIFont(name: "Courier", size: 17)
        
        // Make UITextView Editable
        myTextView.isEditable = true
        
        // Capitalize all characters user types
        // myTextView.autocapitalizationType = UITextAutocapitalizationType.allCharacters
        
        // Make web links clickable
        // myTextView.isSelectable = true
        myTextView.isEditable = true
        myTextView.dataDetectorTypes = UIDataDetectorTypes.link
        
        // Make UITextView corners rounded
        myTextView.layer.cornerRadius = 10
        
        // Enable auto-correction and Spellcheck
        // myTextView.autocorrectionType = UITextAutocorrectionType.yes
        // myTextView.spellCheckingType = UITextSpellCheckingType.yes
        // myTextView.autocapitalizationType = UITextAutocapitalizationType.None
        
        // Add Tap gesture to be able to dismiss keyboard when user taps away
        // You will need to declare a new function "tappedAwayFunction"
        let myGesture = UITapGestureRecognizer(target: self, action: Selector(("tappedAwayFunction:")))
        self.view.addGestureRecognizer(myGesture)

    }
    
    func tappedAwayFunction(sender: UITapGestureRecognizer){
        myTextView.resignFirstResponder()
    }
    internal func textViewDidBeginEditing(_ myTextView: UITextView){
        print("inside of textViewDidBeginEditing")
    }
    
    internal func textViewDidEndEditing(_ myTextView: UITextView){
        print("inside of textViewDidEndEditing")
    }
}

I tried @objc func and internal func as well. When tapping away the keyboard, I'm getting a backtrace:

2019-01-15 14:07:37.957426+0100 DGTest[5636:1935710] [MC] Reading from public effective user settings.
inside of textViewDidBeginEditing
2019-01-15 14:07:40.905753+0100 DGTest[5636:1935710] -[DGTest.ViewController tappedAwayFunction:]: unrecognized selector sent to instance 0x105e07150
2019-01-15 14:07:40.908931+0100 DGTest[5636:1935710] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[DGTest.ViewController tappedAwayFunction:]: unrecognized selector sent to instance 0x105e07150'
*** First throw call stack:
(0x1ad354ec4 0x1ac525a40 0x1ad26dc24 0x1da5183d8 0x1ad35a7dc 0x1ad35c48c 0x1da102f10 0x1da10b52c 0x1da108db0 0x1da108298 0x1da0fb5a0 0x1da0fb10c 0x1da0faedc 0x1da526c74 0x1da505f8c 0x1da5d4df8 0x1da5d77f0 0x1da5d02e0 0x1ad2e51f0 0x1ad2e5170 0x1ad2e4a54 0x1ad2df920 0x1ad2df1f0 0x1af558584 0x1da4eabc0 0x104d110b0 0x1acd9ebb4)
libc++abi.dylib: terminating with uncaught exception of type NSException

Changing to #selector syntax wasn't accepted by the compiler. I ended uo in letting the compiler fix the action: line to

let myGesture = UITapGestureRecognizer(target: self, action: Selector(("tappedAwayFunction:")))
        self.view.addGestureRecognizer(myGesture)

But I'm left with the exception occuring.

Any clues?

--

Christoph

Edit: typo