code: func (c *ConsulProvider) incrementProviderIndex(providerState *structs.CAConsulProviderState) error {
  	newState := *providerState
  	args := &structs.CARequest{
  		Op:            structs.CAOpSetProviderState,
  		ProviderState: &newState,
  	}
  	if err := c.Delegate.ApplyCARequest(args); err != nil {
  		return err
  	}
  
  	return nil
  }
docs: // incrementProviderIndex does a write to increment the provider state store table index
  // used for serial numbers when generating certificates.