refactor annotation

eu_einvoice/european_e_invoice/custom/sales_invoice.py

@@ -781,7 +781,7 @@ def download_pdf(
 			frappe.local.response.filecontent = zugferd_pdf
 
 
-def _create_symlink_to_icc_profile():
+def _create_symlink_to_icc_profile() -> None:
 	"""Create a symlink to the ICC profile in the Ghostscript installation."""
 	import os
 	import re
@@ -841,7 +841,7 @@ def _convert_pdf_to_pdfa(pdf_data: bytes) -> bytes:
 		return pdfa_data
 
 
-def _is_ghostscript_installed():
+def _is_ghostscript_installed() -> bool:
 	"""Check if Ghostscript is installed on the system."""
 	import shutil