validate method Null safety

void validate(
  1. Set<String> validVariables
)

Throws a FormatException if this selector uses 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 validate(Set<String> validVariables) {
  if (identical(this, all)) return;

  _wrapFormatException(
      () => _inner.validate((name) =>
          _universalValidVariables.contains(name) ||
          validVariables.contains(name)),
      _span);
}