set_avatar_async
Description:
[ Version ( since = "0.11.1" ) ]
public async bool set_avatar_async (uint8[]? avatar, string? mime_type) throws Error
  public async bool set_avatar_async (uint8[]? avatar, string? mime_type) throws Error
Requests an asynchronous change of the Avatar parameter on this.
 When the operation is finished, callback will be called. You can then call set_avatar_async.end to
      get the result of the operation.
If avatar.length equals 0, the avatar is cleared.
Parameters:
| this | a Account | 
| avatar | a new avatar to set; can be  | 
| mime_type | the MIME type of the new avatar; can be  | 
| callback | a callback to call when the request is satisfied | 
| len | the length of the new avatar | 
| user_data | data to pass to  |