asMap method
Creates an unmodifiable view of the underlying mappings.
This method provides support for the spread operator by returning a Map that can be spread.
final mappings = {
...RdfNamespaceMappings().asMap(),
'custom': 'http://example.org/custom#'
};
Returns an unmodifiable map of the prefix-to-URI mappings.
Implementation
Map<String, String> asMap() => Map.unmodifiable(_mappings);