presto-accumulo/src/main/java/io/prestosql/plugin/accumulo/AccumuloTableManager.java/AccumuloTableManager/ensureNamespace
class AccumuloTableManager:    public void ensureNamespace(String schema)
    {
        try {
            // If the table schema is not "default" and the namespace does not exist, create it
            if (!schema.equals(DEFAULT) && !connector.namespaceOperations().exists(schema)) {
                connector.namespaceOperations().create(schema);
            }
        }
        catch (AccumuloException | AccumuloSecurityException e) {
            throw new PrestoException(UNEXPECTED_ACCUMULO_ERROR, "Failed to check for existence or create Accumulo namespace", e);
        }
        catch (NamespaceExistsException e) {
            // Suppress race condition between test for existence and creation
            LOG.warn("NamespaceExistsException suppressed when creating " + schema);
        }
    }