[ISSUE] SDK throws null pointer exception when attempting to refresh tokens

[satviksr-db]

Description Dear team, Sometimes the SDK throws null pointer exception when attempting to refresh tokens, I am not entirely sure if there is an issue with the SDK or the API is behaving incorrectly

Caused by: java.lang.NullPointerException: accessToken must be defined
	at java.base/java.util.Objects.requireNonNull(Objects.java:246)
	at com.databricks.sdk.core.oauth.Token.<init>(Token.java:51)
	at com.databricks.sdk.core.oauth.Token.<init>(Token.java:41)
	at com.databricks.sdk.core.oauth.RefreshableTokenSource.retrieveToken(RefreshableTokenSource.java:74)
	at com.databricks.sdk.core.oauth.ClientCredentials.refresh(ClientCredentials.java:104)
	at com.databricks.sdk.core.oauth.RefreshableTokenSource.getToken(RefreshableTokenSource.java:84)
	at com.databricks.sdk.core.oauth.OAuthM2MServicePrincipalCredentialsProvider.lambda$configure$0(OAuthM2MServicePrincipalCredentialsProvider.java:45)
	at com.databricks.sdk.core.DatabricksConfig.authenticate(DatabricksConfig.java:189)

Reproduction A minimal code sample demonstrating the bug.

Expected behavior A clear and concise description of what you expected to happen.

Is it a regression? Did this work in a previous version of the SDK? If so, which versions did you try?

Debug Logs The SDK logs helpful debugging information when debug logging is enabled. Set the log level to TRACE (e.g. add log4j.logger.com.databricks=TRACE to the log4j.properties in your project), and include the logs here.

Other Information

• OS: [e.g. macOS]
• Version: [e.g. 0.1.0]

Additional context Add any other context about the problem here.