geometry: Make parent as optional.

src/Model/Geometry/Reach.py

@@ -16,7 +16,7 @@ from Model.Geometry.ProfileXYZ import ProfileXYZ
 from Model.Except import FileFormatError, exception_message_box
 
 class Reach:
-    def __init__(self, parent):
+    def __init__(self, parent=None):
         self._parent = parent
         self._profiles: List[Profile] = []
 
@@ -39,6 +39,9 @@ class Reach:
 
     @property
     def name(self):
+        if self._parent == None:
+            return ""
+
         return self._parent.name
 
     @property