encodeKeyed method
Starts encoding a keyed collection or key-value pairs.
The returned KeyedEncoder should be used to encode the key-value pairs. The KeyedEncoder.end method should be called when all key-value pairs have been encoded.
Implementation
@override
KeyedEncoder encodeKeyed() {
throw CodableException.unsupportedMethod('CsvEncoder', 'encodeKeyed',
reason: 'Row-level encoding only supports encodeKeyed() and encodeMapped().');
}