function loadHeaderValues(buffer, headerLength) {
  const headerValues = [];
  for (let i = 0; i < headerLength / 4; i++) {
    // Header data is stored in-order (aka big-endian)
    headerValues[i] = buffer.readUInt32BE(i * 4);
  }
  return headerValues;
}
Read the header of the dataset file

@param {Buffer} buffer
@param {number} headerLength

@returns {number[]} MNIST data header values