public BigInteger (int numBits, Random rnd)

Constructs a randomly generated BigInteger, uniformly distributed over
the range 0 to (2^{ numBits} - 1), inclusive.
The uniformity of the distribution assumes that a fair source of random
bits is provided in ` rnd`

. Note that this constructor always
constructs a non-negative BigInteger.

`numBits` | maximum bitLength of the new BigInteger. | |

`rnd` | source of randomness to be used in computing the new BigInteger. |

`IllegalArgumentException` | ` numBits` is negative. |

bitLength()

Diagram: BigInteger, BigDecimal