layer.draggable.speedY < number>

Modify the vertical dragging speed. The value is in pixels per mouse moved pixels. The default value is 1. When set lower then 1 dragging will be slower than mouse movement and vice versa. You can set the value to 0 to disable vertical dragging.
译：修改垂直拖动速度。该值是每鼠标移动像素的像素。默认值是1。如果设置下再1拖动将比鼠标移动较慢的，反之亦然。您可以将值设置为0来禁用垂直拖动。

layerA = new Layer
layerA.draggable.enabled = true

# Make vertical dragging slow 
layerA.draggable.speedY = 0.1

# Make vertical dragging fast 
layerA.draggable.speedY = 10