-    def _source_address(self, command_option):
-        source_address = self.params.get('source_address')
-        if source_address is None:
-            return []
-        return [command_option, source_address]
+    def _option(self, command_option, param):
+        return cli_option(self.params, command_option, param)
+
+    def _bool_option(self, command_option, param, true_value='true', false_value='false', separator=None):
+        return cli_bool_option(self.params, command_option, param, true_value, false_value, separator)
+
+    def _valueless_option(self, command_option, param, expected_value=True):
+        return cli_valueless_option(self.params, command_option, param, expected_value)
+
+    def _configuration_args(self, default=[]):
+        return cli_configuration_args(self.params, 'external_downloader_args', default)