diff --git a/waybackpy/availability_api.py b/waybackpy/availability_api.py
index 5922c4b..11a9716 100644
--- a/waybackpy/availability_api.py
+++ b/waybackpy/availability_api.py
@@ -33,7 +33,8 @@ class WaybackMachineAvailabilityAPI(object):
         self.api_call_time_gap = 5
         self.JSON: Optional[ResponseJSON] = None
 
-    def unix_timestamp_to_wayback_timestamp(self, unix_timestamp: int) -> str:
+    @staticmethod
+    def unix_timestamp_to_wayback_timestamp(unix_timestamp: int) -> str:
         """
         Converts Unix time to wayback Machine timestamp.
         """
@@ -153,7 +154,8 @@ class WaybackMachineAvailabilityAPI(object):
             )
         return archive_url
 
-    def wayback_timestamp(self, **kwargs: int) -> str:
+    @staticmethod
+    def wayback_timestamp(**kwargs: int) -> str:
         """
         Prepends zero before the year, month, day, hour and minute so that they
         are conformable with the YYYYMMDDhhmmss wayback machine timestamp format.
diff --git a/waybackpy/cdx_utils.py b/waybackpy/cdx_utils.py
index cc5b528..fce6acb 100644
--- a/waybackpy/cdx_utils.py
+++ b/waybackpy/cdx_utils.py
@@ -98,8 +98,8 @@ def check_collapses(collapses: List[str]) -> bool:
                 "is not following the cdx collapse syntax."
             )
             raise WaybackError(exc_message)
-    else:
-        return True
+
+    return True
 
 
 def check_match_type(match_type: Optional[str], url: str) -> bool:
diff --git a/waybackpy/save_api.py b/waybackpy/save_api.py
index 3afe40b..29d3b11 100644
--- a/waybackpy/save_api.py
+++ b/waybackpy/save_api.py
@@ -108,7 +108,8 @@ class WaybackMachineSaveAPI(object):
 
         return None
 
-    def sleep(self, tries: int) -> None:
+    @staticmethod
+    def sleep(tries: int) -> None:
         """
         Ensure that the we wait some time before succesive retries so that we
         don't waste the retries before the page is even captured by the Wayback