preprocess method
Converts input text into the model's expected input tensor format.
Default implementation uses char-level encoding via preprocessor. Override for custom preprocessing (tokenization, normalization, etc.).
Implementation
@override
List<List<double>> preprocess(String input) {
// Extract domain part from email
final atIndex = input.lastIndexOf('@');
final domain = atIndex >= 0 ? input.substring(atIndex + 1) : input;
return preprocessor.encodeAsTensor(domain.toLowerCase());
}