           make.left.bottom.equalToSuperview()
         }
         
-        titleLabel.snp.makeConstraints { [weak self](make) in
-          if let `self` = self {
+        titleLabel.snp.makeConstraints { [unowned self](make) in
             make.left.equalTo(self.backButton.snp.right)
             make.centerY.equalTo(self.backButton)
-          }
-        }
-        
-        chooseDefinitionView.snp.makeConstraints { [weak self](make) in
-          if let `self` = self {
+        }
+        
+        chooseDefinitionView.snp.makeConstraints { [unowned self](make) in
             make.right.equalToSuperview().offset(-20)
             make.top.equalTo(self.titleLabel.snp.top).offset(-4)
             make.width.equalTo(60)
             make.height.equalTo(30)
-          }
         }
         
         // Bottom views

    
    func addSnapKitConstraint() {
        // Main mask view
        mainMaskView.snp.makeConstraints { [weak self](make) in
          if let `self` = self {
            make.edges.equalTo(self)
          }
        }
        
        maskImageView.snp.makeConstraints { [weak self](make) in
          if let `self` = self {
            make.edges.equalTo(self.mainMaskView)
          }
        }

        topMaskView.snp.makeConstraints { [weak self](make) in
          if let `self` = self {
            make.top.left.right.equalTo(self.mainMaskView)
          }
        }
        
        topWrapperView.snp.makeConstraints { [weak self](make) in
          if let `self` = self {
            make.height.equalTo(50)
            if #available(iOS 11.0, *) {
              make.top.left.right.equalTo(self.topMaskView.safeAreaLayoutGuide)

            } else {
              make.edges.equalToSuperview()
            }
        }
        
        // Top views
