private final double getRefBinomialProb(final int depth) {
if (depth < binomialProbabilityDepthCache.length) return binomialProbabilityDepthCache[depth];
else return MathUtils.binomialProbability(0, depth, 0.5);
}
static {
for (int i = 1; i < binomialProbabilityDepthCache.length; i++) {
binomialProbabilityDepthCache[i] = MathUtils.binomialProbability(0, i, 0.5);
}
}