fix(writers): ensure variable is assigned before usage

Author: sanjayankur31

neuroml/writers.py

@@ -27,6 +27,8 @@ def write(cls, nmldoc: neuroml.NeuroMLDocument, file: str, close: bool = True):
 
         if isinstance(file, str):
             fileh = open(file, "w")
+        else:
+            fileh = file
 
         # TODO: this should be extracted from the schema:
         namespacedef = 'xmlns="http://www.neuroml.org/schema/neuroml2" '