presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/UserDatabaseKey.java/UserDatabaseKey/equals
class UserDatabaseKey:    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        UserDatabaseKey that = (UserDatabaseKey) o;
        return Objects.equals(user, that.user) &&
                Objects.equals(database, that.database);
    }