docs: function diamondLeftToVic(lead) {
      var m = lead.p;
      var z = lead;
      var x = z.l;
      var y = x.r;
      var a = y.l;
      var b = y.r;
      x.flag = false;
      y.l = x;
      x.p = y;
      y.r = z;
      z.p = y;
      x.r = a;
      a.p = x;
      z.l = b;
      b.p = z;
      if (m.r === lead) {
          m.r = y;
      }
      else {
          m.l = y;
      }
      y.p = m;
      return y;
  }