In this case:

    auto array = Array<u8, 128> {};

    // First line: 8 bytes, second line: 24 bytes, third line, 32 bytes
    array.fill('A');
    array[7] = '\n';
    array[31] = '\n';
    array[63] = '\n';

    auto memory_stream = make<FixedMemoryStream>(array.span(), FixedMemoryStream::Mode::ReadOnly);

    // Buffer for buffered seekable is larger than the stream, so stream goes EOF immediately on read
    auto buffered_stream = TRY_OR_FAIL(InputBufferedSeekable<FixedMemoryStream>::create(move(memory_stream), 32));

    // Buffer is only 16 bytes, first read succeeds, second fails
    auto buffer = TRY_OR_FAIL(ByteBuffer::create_zeroed(16));

    auto read_bytes = TRY_OR_FAIL(buffered_stream->read_line(buffer));
    
    auto read_or_error = buffered_stream->read_line(buffer);
    
    // Oops! only read 16 bytes!

We fail to error out the read_line in the case that the user's buffer is too small for the line.