function removeHTTPWhitespace (str, leading = true, trailing = true) {
  let lead = 0
  let trail = str.length - 1

  if (leading) {
    for (; lead < str.length && isHTTPWhiteSpace(str[lead]); lead++);
  }

  if (trailing) {
    for (; trail > 0 && isHTTPWhiteSpace(str[trail]); trail--);
  }

  return str.slice(lead, trail + 1)
}
@see https://fetch.spec.whatwg.org/#http-whitespace
@param {string} str