code: func (h *RequestHeader) CopyTo(dst *RequestHeader) {
  	dst.Reset()
  
  	dst.disableNormalizing = h.disableNormalizing
  	dst.noHTTP11 = h.noHTTP11
  	dst.connectionClose = h.connectionClose
  
  	dst.contentLength = h.contentLength
  	dst.contentLengthBytes = append(dst.contentLengthBytes[:0], h.contentLengthBytes...)
  	dst.method = append(dst.method[:0], h.method...)
  	dst.requestURI = append(dst.requestURI[:0], h.requestURI...)
  	dst.host = append(dst.host[:0], h.host...)
  	dst.contentType = append(dst.contentType[:0], h.contentType...)
  	dst.userAgent = append(dst.userAgent[:0], h.userAgent...)
  	dst.h = copyArgs(dst.h, h.h)
  	dst.cookies = copyArgs(dst.cookies, h.cookies)
  	dst.cookiesCollected = h.cookiesCollected
  	dst.rawHeaders = append(dst.rawHeaders[:0], h.rawHeaders...)
  	dst.rawHeadersParsed = h.rawHeadersParsed
  	dst.rawHeadersCopy = append(dst.rawHeadersCopy[:0], h.rawHeadersCopy...)
  }
docs: // CopyTo copies all the headers to dst.