code: func (m *Message) IsCommand() bool {
  	if m.Entities == nil || len(*m.Entities) == 0 {
  		return false
  	}
  
  	entity := (*m.Entities)[0]
  	return entity.Offset == 0 && entity.IsCommand()
  }
docs: // IsCommand returns true if message starts with a "bot_command" entity.