function pareto2( alpha, beta ) {
		if (
			isnan( alpha ) ||
			isnan( beta ) ||
			alpha <= 0.0 ||
			beta <= 0.0
		) {
			return NaN;
		}
		return pareto0( rand, alpha, beta );
	}
Returns a pseudorandom number drawn from a Pareto (Type I) distribution.

@private
@param {PositiveNumber} alpha - shape parameter
@param {PositiveNumber} beta - scale parameter
@returns {NonNegativeNumber} pseudorandom number

@example
var v = pareto2( 2.0, 3.0 );
// returns <number>

@example
var v = pareto2( 3.0, 0.0 );
// returns NaN

@example
var v = pareto2( 0.0, 2.0 );
// returns NaN

@example
var v = pareto2( NaN, NaN );
// returns NaN