code: function lengthArray(len) {
      var arr = [];
  
      if (len <= 127) {
          // Return a single byte if the value is 127 or less.
          return [ len ];
      } else {
          // Otherwise encode it as a MSB base-256 integer.
          while (len > 0) {
              arr.push(len % 256);
              len = parseInt(len / 256, 10);
          }
          // Add a length byte in front and set the high bit to indicate
          // that this is a longer value than one byte.
          arr.push(128 + arr.length);
          arr.reverse();
          return arr;
      }
  }
docs: Private helper functions ----- Encode a length as it should be encoded.