code: function _rotateRadian(radiansRaw, radialAdj) {
    radialAdj %= TWOPI;
  
    return _.map(radiansRaw, function(r){
      r += radialAdj;
  
      // for radial positions that cross the baseline, recompute
      if(r > TWOPI) { return r -= TWOPI; }
      if(r < 0) { return r += TWOPI; }
  
      return r;
    });
  }
docs: _rotateRadian rotates a list of radial positions by the desired radian amount
  @param  {Array} radiansRaw  List of radial positions to rotate
  @param  {Float} radialAdj   The radial rotation to apply -- max rotation is 2PI
  @return {Array}             rotates a list of radial positions by the desired radian amount