Partition#get(unknown_partition) returns []

spec/test.cr

@@ -307,6 +307,8 @@ describe "DODB::DataBase" do
 					a && b
 				}.should be_true
 			end
+
+			db_ships_by_class.get("does-not-exist").should eq [] of Ship
 		end
 
 		it "removes select elements from partitions" do

src/dodb/partition.cr

@@ -43,6 +43,9 @@ class DODB::Partition(V) < DODB::Indexer(V)
 		r_value = Array(V).new
 
 		partition_directory = indexing_directory partition
+
+		return r_value unless Dir.exists? partition_directory
+
 		Dir.each_child partition_directory do |child|
 			r_value << V.from_json ::File.read "#{partition_directory}/#{child}"
 		end