Примеры ошибок, обнаруженных с помощью диагностики V6073
V6073. It is not recommended to return null or throw exceptions from 'toString' / 'clone' methods.
Apache Solr
V6073 It is not recommended to return null from 'clone' method. UpdateCommand.java 97
@Override
public UpdateCommand clone() {
try {
return (UpdateCommand) super.clone();
} catch (CloneNotSupportedException e) {
return null; // <=
}
}