docs: function(a, s) {
           return {
              d: function(x, logp) { return dgamma(a, s, logp)(x); },
              p: function(q, lowerTail, logp) {
                 return pgamma(a, s, lowerTail, logp)(q);
              },
              q: function(p, lowerTail, logp) {
                 return qgamma(a, s, lowerTail, logp)(p);
              },
              r: function() { return rgamma(a, s)(); }
           };
        }