Constructor: messageEntityCustomEmoji
Represents a custom emoji.
 Note that this entity must wrap exactly one regular emoji (the one contained in documentAttributeCustomEmoji.alt) in the related text, otherwise the server will ignore it.
Attributes:
| Name | Type | Required | Description | 
|---|---|---|---|
| offset | int | Yes | Offset of message entity within message (in UTF-16 code units) | 
| length | int | Yes | Length of message entity within message (in UTF-16 code units) | 
| document_id | long | Yes | Document ID of the custom emoji, use messages.getCustomEmojiDocuments to fetch the emoji animation and the actual emoji it represents. | 
Type: MessageEntity
Example:
 $messageEntityCustomEmoji = ['_' => 'messageEntityCustomEmoji', 'offset' => int, 'length' => int, 'document_id' => long];