public MapReduceToCollectionOperation action(final String action) {
        notNull("action", action);
        isTrue("action must be one of: \"replace\", \"merge\", \"reduce\"", VALID_ACTIONS.contains(action));
        this.action = action;
        return this;
    }
public MapReduceToCollectionOperation action(final String action) {
        notNull("action", action);
        isTrue("action must be one of: \"replace\", \"merge\", \"reduce\"", VALID_ACTIONS.contains(action));
        this.action = action;
        return this;
    }
public MapReduceToCollectionOperation action ( final String action ) { notNull ( "action" , action ) ; isTrue ( "action must be one of: \"replace\", \"merge\", \"reduce\"" , VALID_ACTIONS . contains ( action ) ) ; this . action = action ; return this ; }
Sets the output action one of: "replace", "merge", "reduce"

@param action the output action
@return this
@mongodb.driver.manual reference/command/mapReduce/#output-to-a-collection-with-an-action output with an action
Sets the output action one of : replace merge reduce