Filesystems.matchSingleFileSpec throws away the actual failure exception

At [1] the result of a non-OK match causes an exception to be thrown. But the exception does not include the actual cause of the failure, so it cannot be efficiently debugged. It appears that the design of MatchResult is that it should call metadata() without bothering to check status, so that the underlying exception can be re-raised and caught and put in the chain of causes, as it should be.

[1] https://github.com/apache/beam/blob/c2f0d282337f3ae0196a7717712396a5a41fdde1/sdks/java/core/src/main/java/org/apache/beam/sdk/io/FileSystems.java#L190