code: func NewDNSProvider() (*DNSProvider, error) {
  	values, err := env.Get("CONOHA_TENANT_ID", "CONOHA_API_USERNAME", "CONOHA_API_PASSWORD")
  	if err != nil {
  		return nil, fmt.Errorf("conoha: %v", err)
  	}
  
  	config := NewDefaultConfig()
  	config.TenantID = values["CONOHA_TENANT_ID"]
  	config.Username = values["CONOHA_API_USERNAME"]
  	config.Password = values["CONOHA_API_PASSWORD"]
  
  	return NewDNSProviderConfig(config)
  }
docs: // NewDNSProvider returns a DNSProvider instance configured for ConoHa DNS.
  // Credentials must be passed in the environment variables: CONOHA_TENANT_ID, CONOHA_API_USERNAME, CONOHA_API_PASSWORD