MemoryIO::read - incorrect number of bytes read:
  size=1, used=61, pos=61, left=0
MemoryIO::seek - cannot seek before start of object
MemoryIO::write - buffer cannot be expanded
MemoryIO::seek - buffer cannot be expanded
MemoryIO::write - buffer cannot be expanded
MemoryIO::seek - buffer cannot be expanded
MemoryIO::write - MemoryIO object is not writable
read/write
readonly
writeonly
