CPPUNIT_ASSERT(stream_out.SeekO(-2, wxFromEnd) != wxInvalidOffset);
// Go beyond the stream size.
CPPUNIT_ASSERT((stream_out.SeekO(10, wxFromCurrent) == wxInvalidOffset) == m_bSeekInvalidBeyondEnd);
CPPUNIT_ASSERT(stream_out.SeekO(-2, wxFromEnd) != wxInvalidOffset);
// Go beyond the stream size.
CPPUNIT_ASSERT((stream_out.SeekO(10, wxFromCurrent) == wxInvalidOffset) == m_bSeekInvalidBeyondEnd);