unusedKeysCheck method
void
unusedKeysCheck()
Checks all the keys in the config map have been processed.
Throws a ConfigExceptionKeyUnexpected if the config map contains keys which have not been referenced by one of the extraction methods (e.g. string, stringOptional, integer).
Throws a ConfigExceptionFormat if an invalid key is found. This is a syntax error which is not detected by the ConfigMap constructor, but is only detected when all the keys are examined.
This method is used for checking a config only contains the expected keys and nothing else. If it throws an exception, either the config is invalid or the program is missing an extraction operation.
Implementation
void unusedKeysCheck() {
keys(permitted: _used.toList(growable: false));
}