writeUint32BigEndian = (encoder, num) => {
  for (let i = 3; i >= 0; i--) {
    write(encoder, num >>> 8 * i & binary.BITS8);
  }
}
Write two bytes as an unsigned integer in big endian order.
(most significant byte first)

@function
@param {Encoder} encoder
@param {number} num The number that is to be encoded.