Parameter default should be null and not a string.

[OGKevin]

sdk_php/src/Context/ApiContext.php

Line 332 in 652e650

public function save(string $fileName = self::FILENAME_CONFIG_DEFAULT)

Instead of giving the default value a proper value, it should be null. Instead the method body we will then check if the parameter is null or not.

This way, in other places we should not check if we are going to pass null or not. e.g.

sdk_php/src/Util/InstallationUtil.php

Lines 169 to 173 in 652e650

	if ($contextFileName === null) {
	$context->save();
	} else {
	$context->save($contextFileName);
	}