Send the right exception for missing entry.

src/cached.cr

@@ -1,3 +1,7 @@
+require "file_utils"
+require "json"
+
+require "./dodb.cr"
 
 #class Hash(K,V)
 #	def reverse
@@ -37,6 +41,7 @@ class DODB::DataBase::Cached(V)
 		self[index] = item
 		self.last_index = index
 		@data[self.last_index] = item
+		self.last_index
 	end
 
 	# Getting data from the hash in RAM.
@@ -49,7 +54,7 @@ class DODB::DataBase::Cached(V)
 	def [](key : Int32) : V
 		# raise MissingEntry.new(key) unless ::File.exists? file_path key
 		# read file_path key
-		@data[key]
+		@data[key] rescue raise MissingEntry.new(key)
 	end
 
 	def []=(index : Int32, value : V)
@@ -301,4 +306,3 @@ class DODB::DataBase::Cached(V)
 		end
 	end
 end
-