code: function Int64(bytes) {
      if (bytes.length !== 8) {
          throw new Error('Int64 buffers must be exactly 8 bytes');
      }
      if (!util.Buffer.isBuffer(bytes)) bytes = toBuffer(bytes);
  
      this.bytes = bytes;
  }
docs: A lossless representation of a signed, 64-bit integer. Instances of this
  class may be used in arithmetic expressions as if they were numeric
  primitives, but the binary representation will be preserved unchanged as the
  `bytes` property of the object. The bytes should be encoded as big-endian,
  two's complement integers.
  @param {Buffer} bytes
  
  @api private