Method draw

tests/fl/fx/fx_engine.cpp:34–39

    MockFx(uint16_t numLeds, CRGB color) : fl::Fx(numLeds), mColor(color) {}

    void draw(fl::Fx::DrawContext ctx) override {
        mLastDrawTime = ctx.now;
        for (uint16_t i = 0; i < mNumLeds; ++i) {
            ctx.leds[i] = mColor;
        }
    }

    fl::string fxName() const override { return "MockFx"; }