code: @Override
    public CompletableFuture<Void> enableTable(TableName tableName) {
      return tableExists(tableName).thenApply(exists -> {
        if (!exists) {
          throw new CompletionException(new TableNotFoundException(tableName));
        } else if (!disabledTables.contains(tableName)) {
          throw new CompletionException(new TableNotDisabledException(tableName));
        } else {
          disabledTables.remove(tableName);
          LOG.warn("Table " + tableName + " was enabled in memory only.");
          return null;
        }
      });
    }
docs: {@inheritDoc}