def default_settings(self, compiler, compiler_version):
        # Set default settings in global defined
        self.paths.conan_config  # For create the default file if not existing
        text = load(self.paths.conan_conf_path)
        # prevent TestClient instances with reused paths to write again the compiler
        if compiler != "Visual Studio":
            text = text.replace("compiler.runtime=MD", "")
        if "compiler=" not in text:
            # text = text.replace("build_type=Release", "")

            text += "\ncompiler=%s" % compiler
            text += "\ncompiler.version=%s" % compiler_version
            if compiler != "Visual Studio":
                text += "\ncompiler.libcxx=libstdc++"
    
            save(self.paths.conan_conf_path, text)
allows to change the default settings in the file, to change compiler, version
dataset/ETHPy150Open conan-io/conan/conans/test/tools.py/TestClient.default_settings