local p = {} local getArgs = require('Module:Arguments').getArgs  function p.Filter(frame) 	local args = getArgs(frame) 	local layers = args[1] or '' 	local filteredLayers = 'W' -- Wikivoyage (i.e. OpenStreetMap) layer is the default one. 	--filteredLayers = extract(layers,'M') --Working alternatives: M (Mapnik) & R (Relief). Remove comment in case of temporary W server issue 	-- Add additional & acceptable layer parameters 	filteredLayers = filteredLayers 		.. extract(layers,'G') -- GPX file from Wikivoyage 		.. extract(layers,'P') -- POI from Wikivoyage NOT displayed 		.. extract(layers,'E') -- add search box inside the map 		.. extract(layers,'D') -- destination from Wikivoyage --[[| Disabling parameters that share user info (e.g. IP) with third parties 		.. extract(layers,'S') -- hill shading from WM server 		.. extract(layers,'H') -- hiking 		.. extract(layers,'C') -- cycling 		.. extract(layers,'B') -- border 		.. extract(layers,'N') -- traffic network 		]] 	return filteredLayers end  function extract(layers, layer) 	if string.match(layers, layer) ~= nil then 		return string.match(layers, layer) 	else 		return '' 	end end  return p