add some basics

structures copy.py

@@ -0,0 +1,23 @@
+class Wire:
+    def __init__(self, from_device, to_device):
+        self.from_device = from_device
+        self.to_device = to_device
+
+
+class Device:
+    def __init__(self, name, model, properties):
+        self.name = name
+        self.model = model
+        self.properties = properties
+
+
+class Switch(Device):
+    pass
+
+
+class Router(Device):
+    pass
+
+
+class Host(Device):
+    pass