Latest version of com.google.api.grpc:proto-google-cloud-spanner-v1
https://javadoc.io/doc/com.google.api.grpc/proto-google-cloud-spanner-v1
Current version 6.60.1
https://javadoc.io/doc/com.google.api.grpc/proto-google-cloud-spanner-v1/6.60.1
package-list path (used for javadoc generation -link option)
https://javadoc.io/doc/com.google.api.grpc/proto-google-cloud-spanner-v1/6.60.1/package-list