Cannot override with a stored property 'leadingConstraint' , Overriding non-open var outside of its defining module xcode 10 - swift

Question

I'm getting this weird error. My Project was working fine and all of a sudden I got these errors. The errors indicated by Xcode:
Cannot override with a stored property 'leadingConstraint'
Overriding non-open var outside of its defining module
I've defined a constraint variable in UITableViewCell, on which it's giving error.
I tried
clean the build folder.
Restarted the Xcode but it's still giving me
that error.
Error
Cell:
import UIKit
class ReceiverChatImageCell: UITableViewCell {
let bubbleBackgroundView: UIView = {
let v = UIView()
v.backgroundColor = UIColor.darkGray
v.layer.cornerRadius = 5
v.layer.masksToBounds = true
v.translatesAutoresizingMaskIntoConstraints = false
return v
}()
public let chatImage: UIImageView = {
let v = UIImageView()
v.contentMode = .scaleAspectFill
v.translatesAutoresizingMaskIntoConstraints = false
v.clipsToBounds = true
return v
}()
var maxMessageLength: CGFloat = 250
var leadingConstraint: NSLayoutConstraint?
var chatMessage: ChatModel! {
didSet {
profileImageView.loadImage(string: chatMessage.imageUrl)
chatImage.loadImage(string: chatMessage.chatImageUrl)
}
}
public let profileImageView: UIImageView = {
let v = UIImageView()
v.image = #imageLiteral(resourceName: "babs")
v.translatesAutoresizingMaskIntoConstraints = false
v.contentMode = .scaleAspectFill
v.clipsToBounds = true
v.layer.cornerRadius = 20
return v
}()
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
commonInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
func commonInit(){
backgroundColor = .clear
addSubview(profileImageView)
addSubview(bubbleBackgroundView)
addSubview(chatImage)
let available: CGFloat = UIScreen.main.bounds.width - 100
if maxMessageLength > available{
maxMessageLength = available - 50
print("Available Space \(maxMessageLength)")
}
// lets set up some constraints for our image
let constraints = [
profileImageView.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 0),
profileImageView.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -8),
profileImageView.widthAnchor.constraint(equalToConstant: 40),
profileImageView.heightAnchor.constraint(equalToConstant: 40),
chatImage.topAnchor.constraint(equalTo: topAnchor, constant: 8),
chatImage.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -24),
chatImage.widthAnchor.constraint(lessThanOrEqualToConstant: maxMessageLength),
chatImage.heightAnchor.constraint(lessThanOrEqualToConstant: 250),
bubbleBackgroundView.topAnchor.constraint(equalTo: chatImage.topAnchor, constant: -8),
bubbleBackgroundView.leadingAnchor.constraint(equalTo: chatImage.leadingAnchor, constant: -16),
bubbleBackgroundView.bottomAnchor.constraint(equalTo: chatImage.bottomAnchor, constant: 8),
bubbleBackgroundView.trailingAnchor.constraint(equalTo: chatImage.trailingAnchor, constant: 16),
]
NSLayoutConstraint.activate(constraints)
leadingConstraint = chatImage.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 60)
leadingConstraint?.isActive = true
}
}
I haven't used this variable outside the cell.
How can I solve this problem?