code: def test_config_formatter():
      example_config = {
          "section_foo": {"option_bar": True, "option_baz": False},
          "section_foo2": {
              "option_bar2": {"option_baz2": True},
              "option_baz3": {"option_baz4": False},
          },
          "section_foo3": {},
      }
  
      config_lines = tuple(CmdConfig._format_config(example_config))
      assert config_lines == (
          "section_foo.option_bar=True",
          "section_foo.option_baz=False",
          "section_foo2.option_bar2.option_baz2=True",
          "section_foo2.option_baz3.option_baz4=False",
      )
  
imports: import pytest
  from dvc.cli import DvcParserError, parse_args
  from dvc.commands.config import CmdConfig
label_desc: Use image node_id 1 for calling a global function with example usage: test_config_formatter() without return types