aggregator: Simplify 'aggregate_options' function definition

The `values` parameter is safe to remove since it is not provided as an
argument by any callers and the remaining arguments are guaranteed to
always be provided by all callers.

src/flake8/options/aggregator.py

@@ -3,26 +3,30 @@
 This holds the logic that uses the collected and merged config files and
 applies the user-specified command-line configuration on top of it.
 """
+import argparse
 import logging
+from typing import List, Tuple
 
 from flake8.options import config
+from flake8.options.manager import OptionManager
 
 LOG = logging.getLogger(__name__)
 
 
-def aggregate_options(manager, config_finder, arglist=None, values=None):
+def aggregate_options(
+    manager,  # type: OptionManager
+    config_finder,  # type: config.ConfigFileFinder
+    argv,  # type: List[str]
+):  # type: (...) -> Tuple[argparse.Namespace, List[str]]
     """Aggregate and merge CLI and config file options.
 
     :param flake8.options.manager.OptionManager manager:
         The instance of the OptionManager that we're presently using.
     :param flake8.options.config.ConfigFileFinder config_finder:
         The config file finder to use.
-    :param list arglist:
-        The list of arguments to pass to ``manager.parse_args``. In most cases
-        this will be None so ``parse_args`` uses ``sys.argv``. This is mostly
-        available to make testing easier.
-    :param argparse.Namespace values:
-        Previously parsed set of parsed options.
+    :param list argv:
+        The list of remaining command-line argumentsthat were unknown during
+        preliminary option parsing to pass to ``manager.parse_args``.
     :returns:
         Tuple of the parsed options and extra arguments returned by
         ``manager.parse_args``.
@@ -30,10 +34,10 @@ def aggregate_options(manager, config_finder, arglist=None, values=None):
         tuple(argparse.Namespace, list)
     """
     # Get defaults from the option parser
-    default_values, _ = manager.parse_args([], values=values)
+    default_values, _ = manager.parse_args([])
     # Get original CLI values so we can find additional config file paths and
     # see if --config was specified.
-    original_values, _ = manager.parse_args(arglist)
+    original_values, _ = manager.parse_args(argv)
 
     # Make our new configuration file mergerator
     config_parser = config.MergedConfigParser(
@@ -79,4 +83,4 @@ def aggregate_options(manager, config_finder, arglist=None, values=None):
         setattr(default_values, dest_name, value)
 
     # Finally parse the command-line options
-    return manager.parse_args(arglist, default_values)
+    return manager.parse_args(argv, default_values)