presto-main/src/main/java/io/prestosql/metadata/Catalog.java/Catalog/getConnector
class Catalog:    public Connector getConnector(CatalogName catalogName)
    {
        if (this.connectorCatalogName.equals(catalogName)) {
            return connector;
        }
        if (informationSchemaId.equals(catalogName)) {
            return informationSchema;
        }
        if (systemTablesId.equals(catalogName)) {
            return systemTables;
        }
        throw new IllegalArgumentException("Unknown connector id: " + catalogName);
    }