Added DataHandler boilerplate

Sources/SwiftNLP/1. Data Collection/HNSWCorpusDataHandler.swift

+//
+//  HNSWCorpusDataHandler.swift
+//
+//
+//  Created by Mingchung Xia on 2024-02-13.
+//
+
+import Foundation
+
+final class HNSWCorpusDataHandler<Scalar: BinaryFloatingPoint & Codable> {
+    private var corpus: HNSWCorpus<Scalar>
+    private var mmapURL: URL? // set default URL
+    
+    init(corpus: HNSWCorpus<Scalar>) {
+        self.corpus = corpus
+    }
+}
+
+extension HNSWCorpusDataHandler {
+    func saveMemoryMap() {
+        
+    }
+    
+    func loadMemoryMap() {
+        
+    }
+}

Sources/SwiftNLP/2. Encoding/ContextFreeEncoder.swift

@@ -69,7 +69,7 @@ class ContextFreeEncoder<Scalar: BinaryFloatingPoint & Codable>: SNLPEncoder {
             return
         }
         dictionary = ContextFreeEncoder<Scalar>.readDictionaryFromFile(url)
-        hnsw = ContextFreeEncoder<Scalar>.readHNSWFromFile(url)
+//        hnsw = ContextFreeEncoder<Scalar>.readHNSWFromFile(url)
     }
     
     subscript(_ token: String) -> [Scalar] {