added suport for chunk read of clusters

creader/ClusterFile.py

@@ -2,5 +2,22 @@
 from . import ClusterFileReader
 
 class ClusterFile(ClusterFileReader):
-    def __init__(self, fname):
-        super().__init__(fname)
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+
+    def __iter__(self):
+        return self
+    
+    def __next__(self):
+        clusters = self.read()
+        if clusters.size == 0:
+            raise StopIteration
+        else:
+            return clusters
+        
+    def __enter__(self):
+        return self
+    
+    def __exit__(self, exc_type, exc_value, traceback):
+        pass