changed the string represenation function

pyneuroml/swc/LoadSWC.py

@@ -67,7 +67,7 @@ def __init__(self, node_id, type_id, x, y, z, radius, parent_id):
         except (ValueError, TypeError) as e:
             raise ValueError(f"Invalid data types in SWC line: {e}")
 
-    def to_string(self):
+    def __str__(self) -> str:
         """
         Returns a human-readable string representation of the node.