Doc(Core): Add doctest in organise_by

mapytex/calculus/core/tree.py

@@ -1550,6 +1550,28 @@ class AssocialTree(Tree):
          | | | > +
          | | | | > x
          | | | | > y
+        >>> t = AssocialTree.from_str('1/2/3/4')
+        >>> T = AssocialTree.from_list('+', [5, t])
+        >>> print(T)
+        +
+         > 5
+         > /
+         | > /
+         | | > /
+         | | | > 1
+         | | | > 2
+         | | > 3
+         | > 4
+        >>> print(T.organise_by(exclude_nodes=["/"]))
+        +
+         > 5
+         > /
+         | > /
+         | | > /
+         | | | > 1
+         | | | > 2
+         | | > 3
+         | > 4
         """
         if self.node not in exclude_nodes:
             groups = {}