clearpilot: initial commit of full source

common/utils.py

@@ -0,0 +1,11 @@
+class Freezable:
+  _frozen: bool = False
+
+  def freeze(self):
+    if not self._frozen:
+      self._frozen = True
+
+  def __setattr__(self, *args, **kwargs):
+    if self._frozen:
+      raise Exception("cannot modify frozen object")
+    super().__setattr__(*args, **kwargs)