Hello, I'm learning SwiftUI by reading Pro SwiftUI book and coding the examples and I have some trouble with the more advanced version of lava lamp. My app crashes when the timer changing animatableData runs too frequently. To remind you, there is a polygon shape changing its shape every 1 second, but the animation takes 3 seconds. That way, as I was able to deduct from lots of print() statements, sometimes SwiftUI tries to compare/calculate animatableData before and after animation and that data have different dimensions, looks like one side is either .zero (of size 1) or 2 times larger than the other and I get index out of bounds error. What exactly causes SwiftUI to change the animatableData's dimensions that way? I thought those dimensions shall be constant.

    public static func +=(lhs: inout [Double], rhs: [Double]) {
        print("lhs size: \(lhs.count)\trhs size: \(rhs.count)")
        for (index, item) in rhs.enumerated() {
            lhs[index] += item
        }
    }

    public static func -=(lhs: inout [Double], rhs: [Double]) {
        print("lhs size: \(lhs.count)\trhs size: \(rhs.count)")
        for (index, item) in rhs.enumerated() {
            lhs[index] -= item
        }
    }

lhs size: 8 rhs size: 8
lhs size: 8 rhs size: 1
lhs size: 1 rhs size: 8
Swift/ContiguousArrayBuffer.swift:613: Fatal error: Index out of range