!
@abstract Determine whether a given htsFile contains a valid EOF block
@return 3 for a non-EOF checkable filetype;
2 for an unseekable file type where EOF cannot be checked;
1 for a valid EOF block;
0 for if the EOF marker is absent when it should be present;
-1 (with errno set) on failure
@discussion
Check if the BGZF end-of-file (EOF) marker is present
! @abstract Determine whether a given htsFile contains a valid EOF block @return 3 for a non-EOF checkable filetype; 2 for an unseekable file type where EOF cannot be checked; 1 for a valid EOF block; 0 for if the EOF marker is absent when it should be present; -1 (with errno set) on failure @discussion Check if the BGZF end-of-file (EOF) marker is present