docs: @SuppressWarnings("checkstyle:magicnumber")
      private static double phi(long timeDiffMillis, double meanMillis, double stdDeviationMillis) {
          double y = (timeDiffMillis - meanMillis) / stdDeviationMillis;
          double e = Math.exp(-y * (1.5976 + 0.070566 * y * y));
          if (timeDiffMillis > meanMillis) {
              return -Math.log10(e / (1.0 + e));
          } else {
              return -Math.log10(1.0 - 1.0 / (1.0 + e));
          }
      }