don't need the old non-air-above find nodes call anymore

only very old minetest engine lacks the air-above api call

init.lua

@@ -85,7 +85,7 @@ biome_lib.perlin_humidity = PerlinNoise(humidity_seeddiff, humidity_octaves, hum
 -- Local functions
 
 local function get_biome_data(pos, perlin_fertile)
-	local fertility = perlin_fertile:get2d({x=pos.x, y=pos.z})
+	local fertility = perlin_fertile:get_2d({x=pos.x, y=pos.z})
 
 	if type(minetest.get_biome_data) == "function" then
 		local data = minetest.get_biome_data(pos)
@@ -408,25 +408,8 @@ function biome_lib:generate_block_with_air_checking()
 	local blockhash =	minetest.hash_node_position(minp)
 
 	if not biome_lib.surface_nodes_aircheck.blockhash then
-
-		if type(minetest.find_nodes_in_area_under_air) == "function" then -- use newer API call
 		biome_lib.surface_nodes_aircheck.blockhash =
 			minetest.find_nodes_in_area_under_air(minp, maxp, biome_lib.surfaceslist_aircheck)
-		else
-			local search_area = minetest.find_nodes_in_area(minp, maxp, biome_lib.surfaceslist_aircheck)
-
-			-- search the generated block for air-bounded surfaces the slow way.
-
-			biome_lib.surface_nodes_aircheck.blockhash = {}
-
-			for i = 1, #search_area do
-			local pos = search_area[i]
-				local p_top = { x=pos.x, y=pos.y+1, z=pos.z }
-				if minetest.get_node(p_top).name == "air" then
-					biome_lib.surface_nodes_aircheck.blockhash[#biome_lib.surface_nodes_aircheck.blockhash + 1] = pos
-				end
-			end
-		end
 		biome_lib.actioncount_aircheck.blockhash = 1
 
 	else

mod.conf

@@ -1 +1,2 @@
 name = biome_lib
+min_minetest_version = 5.2.0