Refactor some code in timezone module

lib/ansible/modules/extras/system/timezone.py

@@ -218,6 +218,12 @@ class Timezone(object):
         """
         self.abort('set(key, value) is not implemented on target platform')
 
+    def _verify_timezone(self):
+        tz = self.value['name']['planned']
+        tzfile = '/usr/share/zoneinfo/%s' % tz
+        if not os.path.isfile(tzfile):
+            self.abort('given timezone "%s" is not available' % tz)
+
 
 class SystemdTimezone(Timezone):
     """This is a Timezone manipulation class systemd-powered Linux.
@@ -241,10 +247,7 @@ class SystemdTimezone(Timezone):
         self.status = dict()
         # Validate given timezone
         if 'name' in self.value:
-            tz = self.value['name']['planned']
+            self._verify_timezone()
-            tzfile = '/usr/share/zoneinfo/%s' % tz
-            if not os.path.isfile(tzfile):
-                self.abort('given timezone "%s" is not available' % tz)
 
     def _get_status(self, phase):
         if phase not in self.status:
@@ -298,10 +301,7 @@ class NosystemdTimezone(Timezone):
         super(NosystemdTimezone, self).__init__(module)
         # Validate given timezone
         if 'name' in self.value:
-            tz = self.value['name']['planned']
+            self._verify_timezone()
-            tzfile = '/usr/share/zoneinfo/%s' % tz
-            if not os.path.isfile(tzfile):
-                self.abort('given timezone "%s" is not available' % tz)
             self.update_timezone  = self.module.get_bin_path('cp', required=True)
             self.update_timezone += ' %s /etc/localtime' % tzfile
         self.update_hwclock = self.module.get_bin_path('hwclock', required=True)