validatePlatformSelectors method
Throws a FormatException if any PlatformSelectors use any variables
that don't appear either in validVariables
or in the set of variables
that are known to be valid for all selectors.
Implementation
void validatePlatformSelectors(Set<String> validVariables) {
testOn.validate(validVariables);
onPlatform.forEach((selector, metadata) {
selector.validate(validVariables);
metadata.validatePlatformSelectors(validVariables);
});
}