importPrefix method
Get the import prefix of container in the current file generator.
Note that just calling this does not import the container in the current
file. This just assigns an prefix to the container in the current file
generator.
Implementation
String importPrefix(ProtobufContainer container) {
final protoFilePath = container.fileGen!.protoFileUri.toString();
return _importPrefixes.putIfAbsent(
protoFilePath,
() => '\$${_importPrefixes.length}',
);
}