/*!
* @mfn FileExtensions
*
* @headerfile <seqan/basic.h>
*
* @brief Returns an array of file format extension strings for file foramt tag.
*
* @signature FileExtensions<TFormat[, TDummy]>::VALUE;
*
* @tparam TTag The file format tag to use for the query.
* @tparam TDummy Implementation detail, defaults to <tt>void</tt> and is
* ignored.
*
* @return VALUE The array of file format extension, of type <tt>char const
* *[]</tt>.
*
* This metafunction must be implemented in the modules implementing the file
* I/O. The metafunction is predefined when <tt>TTag</tt> is @link Nothing
* @endlink. In this case, <tt>VALUE</tt> is <tt>{""}</tt>.
*/