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