presto-main/src/main/java/io/prestosql/connector/system/SystemTablesMetadata.java/SystemTablesMetadata/getColumnHandles
class SystemTablesMetadata:    @Override
    public Map<String, ColumnHandle> getColumnHandles(ConnectorSession session, ConnectorTableHandle tableHandle)
    {
        ConnectorTableMetadata tableMetadata = checkAndGetTable(session, tableHandle).getTableMetadata();
        return toSystemColumnHandles(tableMetadata);
    }