Net::HTTPResponse.each_response_header

# File tmp/rubies/ruby-3.4.1/lib/net/http/response.rb, line 170
def each_response_header(sock)
  key = value = nil
  while true
    line = sock.readuntil("\n", true).sub(/\s+\z/, '')
    break if line.empty?
    if line[0] == ?\s or line[0] == ?\t and value
      value << ' ' unless value.empty?
      value << line.strip
    else
      yield key, value if key
      key, value = line.strip.split(/\s*:\s*/, 2)
      raise Net::HTTPBadResponse, 'wrong header line format' if value.nil?
    end
  end
  yield key, value if key
end