Variable EasingConst

Easing: Readonly<
    {
        Back: Readonly<EasingFunctionGroup>;
        Bounce: Readonly<EasingFunctionGroup>;
        Circular: Readonly<EasingFunctionGroup>;
        Cubic: Readonly<EasingFunctionGroup>;
        Elastic: Readonly<EasingFunctionGroup>;
        Exponential: Readonly<EasingFunctionGroup>;
        generatePow(power?: number): EasingFunctionGroup;
        Linear: Readonly<EasingFunctionGroup & { None: EasingFunction }>;
        Quadratic: Readonly<EasingFunctionGroup>;
        Quartic: Readonly<EasingFunctionGroup>;
        Quintic: Readonly<EasingFunctionGroup>;
        Sinusoidal: Readonly<EasingFunctionGroup>;
    },
> = ...