Merge upstream and update generated code for v601

OPENAPI_VERSION

@@ -1 +1 @@
-v600
+v601

issuing_token.go

@@ -217,7 +217,7 @@ type IssuingTokenNetworkData struct {
 	WalletProvider *IssuingTokenNetworkDataWalletProvider `json:"wallet_provider"`
 }
 
-// An issuing token object is created when an issued card is added to a digital wallet. As a [card issuer](https://stripe.com/docs/issuing), you can view and manage these tokens through Stripe.
+// An issuing token object is created when an issued card is added to a digital wallet. As a [card issuer](https://stripe.com/docs/issuing), you can [view and manage these tokens](https://stripe.com/docs/issuing/controls/token-management) through Stripe.
 type IssuingToken struct {
 	APIResource
 	// Card associated with this token.

source.go

@@ -6,8 +6,6 @@
 
 package stripe
 
-import "encoding/json"
-
 // The status of the code verification, either `pending` (awaiting verification, `attempts_remaining` should be greater than 0), `succeeded` (successful verification) or `failed` (failed verification, cannot be verified anymore as `attempts_remaining` should be 0).
 type SourceCodeVerificationStatus string
 
@@ -626,22 +624,3 @@ type Source struct {
 	Usage  SourceUsage   `json:"usage"`
 	WeChat *SourceWeChat `json:"wechat"`
 }
-
-// UnmarshalJSON handles deserialization of a Source.
-// This custom unmarshaling is needed because the resulting
-// property may be an id or the full struct if it was expanded.
-func (s *Source) UnmarshalJSON(data []byte) error {
-	if id, ok := ParseID(data); ok {
-		s.ID = id
-		return nil
-	}
-
-	type source Source
-	var v source
-	if err := json.Unmarshal(data, &v); err != nil {
-		return err
-	}
-
-	*s = Source(v)
-	return nil
-}

stripe.go

@@ -1190,8 +1190,7 @@ func Int64Slice(v []int64) []*int64 {
 	return out
 }
 
-// NewBackends creates a new set of backends with the given HTTP client. You
-// should only need to use this for testing purposes or on App Engine.
+// NewBackends creates a new set of backends with the given HTTP client.
 func NewBackends(httpClient *http.Client) *Backends {
 	apiConfig := &BackendConfig{HTTPClient: httpClient}
 	connectConfig := &BackendConfig{HTTPClient: httpClient}
@@ -1203,6 +1202,16 @@ func NewBackends(httpClient *http.Client) *Backends {
 	}
 }
 
+// NewBackendsWithConfig creates a new set of backends with the given config for all backends.
+// Useful for setting up client with a custom logger and http client.
+func NewBackendsWithConfig(config *BackendConfig) *Backends {
+	return &Backends{
+		API:     GetBackendWithConfig(APIBackend, config),
+		Connect: GetBackendWithConfig(ConnectBackend, config),
+		Uploads: GetBackendWithConfig(UploadsBackend, config),
+	}
+}
+
 // ParseID attempts to parse a string scalar from a given JSON value which is
 // still encoded as []byte. If the value was a string, it returns the string
 // along with true as the second return value. If not, false is returned as the