presto-mongodb/src/main/java/io/prestosql/plugin/mongodb/MongoSession.java/MongoSession/getTableMetadataNames
class MongoSession:    private Set<String> getTableMetadataNames(String schemaName)
            throws TableNotFoundException
    {
        MongoDatabase db = client.getDatabase(schemaName);
        MongoCursor<Document> cursor = db.getCollection(schemaCollection)
                .find().projection(new Document(TABLE_NAME_KEY, true)).iterator();

        HashSet<String> names = new HashSet<>();
        while (cursor.hasNext()) {
            names.add((cursor.next()).getString(TABLE_NAME_KEY));
        }

        return names;
    }