function _tagMatch(match, type) {
        switch (type) {
        case BEZIER:
            match.isBezier = true;
            break;
        case STEP:
            match.isStep = true;
            break;
        }

        return match;
    }
Tag this match with type and return it for chaining

@param {!RegExp.match} match  RegExp Match object with steps function parameters
                             in array position 1 (and optionally 2).
@param {number} type Either BEZIER or STEP
@return {RegExp.match} Same object that was passed in.