code: function (seed) {
          if (seed === undefined) {
              seed = new Date().getTime();
          }
          /* Period parameters */
          this.N = 624;
          this.M = 397;
          this.MATRIX_A = 0x9908b0df;   /* constant vector a */
          this.UPPER_MASK = 0x80000000; /* most significant w-r bits */
          this.LOWER_MASK = 0x7fffffff; /* least significant r bits */
  
          this.mt = new Array(this.N); /* the array for the state vector */
          this.mti = this.N + 1; /* mti==N + 1 means mt[N] is not initialized */
  
          this.init_genrand(seed);
      }
docs: Mersenne Twister from https://gist.github.com/banksean/300494