added multiple selection and corresponding features

src/graph/node.py

@@ -1,5 +1,6 @@
 class Node:
-    def __init__(self, x: int, z: int, name: str):
+    def __init__(self, x: int, z: int, name: str, index: int):
         self.x: int = x
         self.z: int = z
+        self.index: int = index
         self.name: str = name