             return
         }
         
-        let previousView = subviews[index - 1]
         let previousInsets = delegate?.stackedView(self, spacingForView: previousView) ?? UIEdgeInsets.zero
         
         let constraints = NSLayoutConstraint.constraints(

                multiplier: 1.0,
                constant: constant
            )
        } else {
            constraint = NSLayoutConstraint(
                item: self,

            multiplier: 1.0,
            constant: constant
        )
        constraint.identifier = "Bottom constraint of stack"
        self.bottomConstraint = constraint
        self.addConstraint(constraint)
    }
