type context struct {
	table [256]byte
}

// Encodes data in place
func (c *context) encode(data []byte) {
	for index, value := range data {
	for dataIndex, dataValue := range data {
		// Loop over the MTF table
		for i := byte(0); i <= 255; i++ {
			if c.table[i] == value {
		for tableIndex, tableValue := range c.table {
			if tableValue == dataValue {
				// Output the value
				data[index] = i
				data[dataIndex] = byte(tableIndex)

				// Shift the table
				copy(c.table[1:], c.table[:i])
				copy(c.table[1:], c.table[:tableIndex])

				// Restore the value in front and break
				c.table[0] = value
				c.table[0] = dataValue
				break
			}
		}
	}
}

// Decode data in place

	io.Copy(&output, decoder)
	processed := output.Bytes()

	delta := diff.Diff(diff.D{Len1: len(data), Len2: len(processed),
		EqualFunc: func(i, j int) bool { return data[i] == processed[j] }})
	if len(delta.Added) > 0 || len(delta.Removed) > 0 {
		t.Error("Differences detected ", delta)
		t.Error("Differences detected ", delta, processed)
	}
}