Represents a non-fatal diagnostic deposited on ZipReader#warnings, EntryMetaData#warnings or ZipWriter#warnings.
Optional
The filename of the first entry the warning applies to, when it applies to an entry.
The reason of the warning, one of the exported WARNING_* constants.
WARNING_*
Represents a non-fatal diagnostic deposited on ZipReader#warnings, EntryMetaData#warnings or ZipWriter#warnings.