$$ quantization $$ Define a Python class called FixedPoint for converting and storing an arbitrary $($e$.$g$.,$

floating$-$point$)$ array in fixed$-$pointed notation. The class must contain the following instance variables$/$properties:

$$ arr: the quantized $($fixed$-$point$)$ representation.

$$ n: the number of bits for the mantissa $($excluding the sign bit$).$

$$ r: the number of fractional bits $($can be negative$).$