This function implements pseudo-random number generation for a Beta distribution for \(\max(\alpha,\beta)<1\) with pdf
$$f(x|\alpha,\beta)=\frac{1}{B(\alpha,\beta)}x^{\alpha-1}(1-x)^{\beta-1}$$
for \(0 \leq x \leq 1\), \(0 < \alpha < 1\), and \(0 < \beta < 1\) where \(\alpha\) and \(\beta\) are the shape parameters and \(B(\alpha,\beta)\) is the complete beta function.