docs: function registerEffect(suffix, animation) {
    if (_.isObject(suffix)) {
      animation = suffix;
      suffix = '';
    }
  
    var key = 'VelocityHelper.animation.' + effectCounter++ + suffix;
  
    // No-op on the server for now.
    if (Velocity.velocityReactServerShim) {
      return key;
    }
  
    if (Velocity.RegisterEffect === undefined) {
      throw "Velocity.RegisterEffect not found. You need to require 'velocity-animate/velocity.ui' at a top level for UI Pack.";
    }
  
    Velocity.RegisterEffect(key, animation);
    return key;
  }