====== getLightByPos ======

  * Parameters and types:
      * x,y,z: numberposition
  * Return value and type:
    * code: numberSuccess (ErrorCode.OK) ErrorCode
    * lv: numberlight intensity (0~16)
  * The main function of this method is to obtain the light intensity
  * The specific use cases are as follows:
<code>
local code, lv = World:getLightByPos(x, y, z)
if code == ErrorCode.OK then
	print('Execution successful', code, lv )
else
	print('Execution failed')
end
</code>