sanitizeNaNValuesWith(vector) {
        this._x = isNaN(this._x) ? vector.x : parseFloat(this._x);
        this._y = isNaN(this._y) ? vector.y : parseFloat(this._y);

        return this;
    }
Merges this vector with a vector when values are NaN. Mostly used internally.

     params:
     @vector (Vec2): vector to use for sanitization

     returns:
     @vector (Vec2): sanitized vector
*