Switch from ArrayList to List in Graph.

src/test/org/insa/graph/PathTest.java

@@ -0,0 +1,20 @@
+package org.insa.graph;
+
+import java.io.IOException;
+import java.util.Arrays;
+
+import org.junit.jupiter.api.BeforeAll;
+
+public class PathTest {
+
+    // Small graph use for tests
+    private Graph graph;
+
+    @BeforeAll
+    static void initAll() throws IOException {
+        Node[] nodes = new Node[] {};
+
+        graph = new Graph(0, Arrays.asList(nodes));
+    }
+
+}