public void Dispose()

// Must be called within QueuedTask.Run9)
public bool TableExists(Geodatabase geodatabase, string tableName)
{
    try
    {
        TableDefinition tableDefinition = geodatabase.GetDefinition<TableDefinition>(tableName);
        tableDefinition.Dispose();
        return true;
    }
    catch
    {
        // GetDefinition throws an exception if the definition doesn't exist
        return false;
    }
}

// Must be called within QueuedTask.Run()
public bool FeatureClassExists(Geodatabase geodatabase, string featureClassName)
{
    try
    {
        FeatureClassDefinition featureClassDefinition = geodatabase.GetDefinition<FeatureClassDefinition>(featureClassName);
        featureClassDefinition.Dispose();
        return true;
    }
    catch
    {
        // GetDefinition throws an exception if the definition doesn't exist
        return false;
    }
}