FileSystemManager.resolveFile(File, String) says that the first parameter may be null. When I pass null, a NullPointerException is thrown.
FileSystem.getLastModTimeAccuracy: the @return clause is not grammatically correct.
SftpFileSystemConfigBuilder.setCompression: mentions the "jsch documentation"; first, jsch does not have documentation, second, the reference should be a little more specific.
SftpFileSystemConfigBuilder.getCompression: should be aligned with the setCompression documentation: when I pass "zlib,none", it is not returned as "the compression algorithm", but as a comma-separated list of compression algorithms.
SftpFileSystemConfigBuilder.setTimeout does not mention the time unit. It is milliseconds.
FtpFileSystemConfigBuilder.setTimeout does not mention the time unit. Same for getSoTimeout