}
		// See if our heap would grow to be too large, and if so, copy it to the end
		// of the mmapped area.
		if heapLen > maxOutBufHeapLen && out.copyHeap() {
			heapPos -= heapLen
			lenNeeded = heapPos + lenToWrite
			heapLen = 0
		}
		out.heap = append(out.heap, make([]byte, lenNeeded-heapLen)...)
	}
	return heapPos, out.heap
}

func (out *OutBuf) SeekSet(p int64) {
	out.off = p
}

	}
}

// TestWriteLoc ensures that the math surrounding writeLoc is correct.
func TestWriteLoc(t *testing.T) {
	tests := []struct {
		bufLen          int
		off             int64
		heapLen         int
		lenToWrite      int64
		expectedHeapLen int
		writePos        int64
		addressInHeap   bool
	}{
		{100, 0, 0, 100, 0, 0, false},
		{100, 100, 0, 100, 100, 0, true},
		{10, 10, 0, 100, 100, 0, true},