func (api *Client) AddReaction(name string, item ItemRef) error {
	return api.AddReactionContext(context.Background(), name, item)
}
AddReaction adds a reaction emoji to a message, file or file comment.
package slack
import (
	"context"
	"net/url"
	"strconv"
)
type ItemReaction struct {
	Name  string   `json:"name"`
	Count int      `json:"count"`
	Users []string `json:"users"`
}
type ReactedItem struct {
	Item
	Reactions []ItemReaction
}
type GetReactionsParameters struct {
	Full bool
}
func NewGetReactionsParameters() GetReactionsParameters {
	return GetReactionsParameters{
		Full: false,
	}
}
type getReactionsResponseFull struct {
	Type string
	M    struct {
		Reactions []ItemReaction
	} `json:"message"`
	F struct {
		Reactions []ItemReaction
	} `json:"file"`
	FC struct {
		Reactions []ItemReaction
	} `json:"comment"`
	SlackResponse
}
func (res getReactionsResponseFull) extractReactions() []ItemReaction {
	switch res.Type {
	case "message":
		return res.M.Reactions
	case "file":
		return res.F.Reactions
	case "file_comment":
		return res.FC.Reactions
	}
	return []ItemReaction{}
}
const (
	DEFAULT_REACTIONS_USER  = ""
	DEFAULT_REACTIONS_COUNT = 100
	DEFAULT_REACTIONS_PAGE  = 1
	DEFAULT_REACTIONS_FULL  = false
)
type ListReactionsParameters struct {
	User  string
	Count int
	Page  int
	Full  bool
}
func NewListReactionsParameters() ListReactionsParameters {
	return ListReactionsParameters{
		User:  DEFAULT_REACTIONS_USER,
		Count: DEFAULT_REACTIONS_COUNT,
		Page:  DEFAULT_REACTIONS_PAGE,
		Full:  DEFAULT_REACTIONS_FULL,
	}
}
type listReactionsResponseFull struct {
	Items []struct {
		Type    string
		Channel string
		M       struct {
			*Message
		} `json:"message"`
		F struct {
			*File
			Reactions []ItemReaction
		} `json:"file"`
		FC struct {
			*Comment
			Reactions []ItemReaction
		} `json:"comment"`
	}
	Paging `json:"paging"`
	SlackResponse
}
func (res listReactionsResponseFull) extractReactedItems() []ReactedItem {
	items := make([]ReactedItem, len(res.Items))
	for i, input := range res.Items {
		item := ReactedItem{}
		item.Type = input.Type
		switch input.Type {
		case "message":
			item.Channel = input.Channel
			item.Message = input.M.Message
			item.Reactions = input.M.Reactions
		case "file":
			item.File = input.F.File
			item.Reactions = input.F.Reactions
		case "file_comment":
			item.File = input.F.File
			item.Comment = input.FC.Comment
			item.Reactions = input.FC.Reactions
		}
		items[i] = item
	}
	return items
}