CollorAPI.BuilderVerticalSpaces.swift

//---- VerticalSpace.swift
public typealias VerticalSpace = CGFloat

public extension CGFloat {
    public static var zero: VerticalSpace = 0
    public static var small: VerticalSpace = 5
    public static var medium: VerticalSpace = 10
    public static var big: VerticalSpace = 20
    public static var huge: VerticalSpace = 40
}

//---- Builder.swift

// new propertie
private(set) var verticalSpaces = [Int: VerticalSpace]()

// new method
public func add(verticalSpace: VerticalSpace) {
    let index = cells.indices.last ?? 0
    verticalSpaces[index] = verticalSpace
}