Swift - TableViewCell - Layout margin not working - swift

Question

I have a table view which should display comments with their replies. Whenever the replies are shown, there should be a margin on the left side so it is clear that a particular reply belongs to the comment above.
To achieve that, I tried following:
class CommentsTableViewCell: UITableViewCell {
// label containing name of comment writer
private func initSenderLabel() {
senderLabel.translatesAutoresizingMaskIntoConstraints = false
self.contentView.addSubview(senderLabel)
senderLabel.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor, constant: 18).isActive = true
senderLabel.widthAnchor.constraint(equalToConstant: 150).isActive = true
senderLabel.topAnchor.constraint(equalTo: self.contentView.topAnchor, constant: 6).isActive = true
senderLabel.heightAnchor.constraint(equalToConstant:14).isActive = true
senderLabel.font = .boldSystemFont(ofSize: 14)
senderLabel.adjustsFontSizeToFitWidth = true
senderLabel.textColor = .gray
}
// actual comment
private func initCommentLabel() {
commentLabel.translatesAutoresizingMaskIntoConstraints = false
self.contentView.addSubview(commentLabel)
commentLabel.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor, constant: 18).isActive = true
commentLabel.widthAnchor.constraint(equalToConstant: 209).isActive = true
commentLabel.topAnchor.constraint(equalTo: self.senderLabel.bottomAnchor, constant: 2).isActive = true
commentLabel.bottomAnchor.constraint(equalTo: self.contentView.bottomAnchor, constant: -29).isActive = true
commentLabel.font = .boldSystemFont(ofSize: 16)
commentLabel.textColor = .black
commentLabel.lineBreakMode = .byWordWrapping
commentLabel.numberOfLines = 0
}
// button to load replies
private func initLoadReplyButton() {
loadReplyButton.translatesAutoresizingMaskIntoConstraints = false
self.contentView.addSubview(loadReplyButton)
loadReplyButton.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor, constant: 50).isActive = true
loadReplyButton.widthAnchor.constraint(equalToConstant: 150).isActive = true
loadReplyButton.topAnchor.constraint(equalTo: commentLabel.bottomAnchor, constant: 0).isActive = true
loadReplyButton.heightAnchor.constraint(equalToConstant: 24).isActive = true
loadReplyButton.addTarget(self, action: #selector(loadReplyButton_touched), for: .touchDown)
loadReplyButton.setTitle(NSLocalizedString(LOAD_REPLIES_BUTTON_TITLE, comment: ""), for: .normal)
loadReplyButton.backgroundColor = .clear
loadReplyButton.setTitleColor(.darkGray, for: .normal)
}
// Sets up the cell using the comment data
func setup(comment: Comment, sender:String) {
// Assign comment
self.commentObject = comment
// Update UI depending if it is a comment or reply
if comment is CommentReply {
loadReplyButton.isHidden = true
contentView.layoutMargins = UIEdgeInsets(top: 0, left: 150, bottom: 0, right: 0)
}
else {
// Remove insets
loadReplyButton.isHidden = false
UIView.setAnimationsEnabled(false)
updateButtonTitle()
UIView.setAnimationsEnabled(true)
}
if !comment.hasReplies {
loadReplyButton.isHidden = true
}
// Update size layout
self.layoutIfNeeded()
}
However, the code above still shows me the replies as it does for the "normal" comments. How can I modify the position of the replies?