# File net/http.rb, line 1163
    def [](key)
      a = @header[key.downcase] or return nil
      a.join(', ')
    end

# File net/http.rb, line 1169
    def []=(key, val)
      unless val
        @header.delete key.downcase
        return val
      end
      @header[key.downcase] = [val]
    end

# File net/http.rb, line 1192
    def add_field(key, val)
      if @header.key?(key.downcase)
        @header[key.downcase].push val
      else
        @header[key.downcase] = [val]
      end
    end

# File net/http.rb, line 1448
    def basic_auth(account, password)
      @header['authorization'] = [basic_encode(account, password)]
    end

# File net/http.rb, line 1359
    def chunked?
      return false unless @header['transfer-encoding']
      field = self['Transfer-Encoding']
      (/(?:\A|[^\-\w])chunked(?![\-\w])/i =~ field) ? true : false
    end

# File net/http.rb, line 1340
    def content_length
      return nil unless key?('Content-Length')
      len = self['Content-Length'].slice(/\d+/) or
          raise HTTPHeaderSyntaxError, 'wrong Content-Length format'
      len.to_i
    end

# File net/http.rb, line 1347
    def content_length=(len)
      unless len
        @header.delete 'content-length'
        return nil
      end
      @header['content-length'] = [len.to_i.to_s]
    end

# File net/http.rb, line 1368
    def content_range
      return nil unless @header['content-range']
      m = %r<bytes\s+(\d+)-(\d+)/(\d+|\*)>i.match(self['Content-Range']) or
          raise HTTPHeaderSyntaxError, 'wrong Content-Range format'
      m[1].to_i .. m[2].to_i + 1
    end

# File net/http.rb, line 1383
    def content_type
      return nil unless main_type()
      if sub_type()
      then "#{main_type()}/#{sub_type()}"
      else main_type()
      end
    end

# File net/http.rb, line 1255
    def delete(key)
      @header.delete(key.downcase)
    end

# File net/http.rb, line 1270
    def each_capitalized
      @header.each do |k,v|
        yield capitalize(k), v.join(', ')
      end
    end

# File net/http.rb, line 1241
    def each_capitalized_name(&block)   #:yield: +key+
      @header.each_key do |k|
        yield capitalize(k)
      end
    end

# File net/http.rb, line 1225
    def each_header   #:yield: +key+, +value+
      @header.each do |k,va|
        yield k, va.join(', ')
      end
    end

# File net/http.rb, line 1234
    def each_name(&block)   #:yield: +key+
      @header.each_key(&block)
    end

# File net/http.rb, line 1248
    def each_value   #:yield: +value+
      @header.each_value do |va|
        yield va.join(', ')
      end
    end

# File net/http.rb, line 1219
    def fetch(key, *args, &block)   #:yield: +key+
      a = @header.fetch(key.downcase, *args, &block)
      a.join(', ')
    end

# File net/http.rb, line 1211
    def get_fields(key)
      return nil unless @header[key.downcase]
      @header[key.downcase].dup
    end

# File net/http.rb, line 1146
    def initialize_http_header(initheader)
      @header = {}
      return unless initheader
      initheader.each do |key, value|
        warn "net/http: warning: duplicated HTTP header: #{key}" if key?(key) and $VERBOSE
        @header[key.downcase] = [value.strip]
      end
    end

# File net/http.rb, line 1260
    def key?(key)
      @header.key?(key.downcase)
    end

# File net/http.rb, line 1393
    def main_type
      return nil unless @header['content-type']
      self['Content-Type'].split(';').first.to_s.split('/')[0].to_s.strip
    end

# File net/http.rb, line 1453
    def proxy_basic_auth(account, password)
      @header['proxy-authorization'] = [basic_encode(account, password)]
    end

# File net/http.rb, line 1285
    def range
      return nil unless @header['range']
      self['Range'].split(/,/).map {|spec|
        m = /bytes\s*=\s*(\d+)?\s*-\s*(\d+)?/i.match(spec) or
                raise HTTPHeaderSyntaxError, "wrong Range: #{spec}"
        d1 = m[1].to_i
        d2 = m[2].to_i
        if    m[1] and m[2] then  d1..d2
        elsif m[1]          then  d1..-1
        elsif          m[2] then -d2..-1
        else
          raise HTTPHeaderSyntaxError, 'range is not specified'
        end
      }
    end

# File net/http.rb, line 1376
    def range_length
      r = content_range() or return nil
      r.end - r.begin
    end

# File net/http.rb, line 1423
    def set_content_type(type, params = {})
      @header['content-type'] = [type + params.map{|k,v|"; #{k}=#{v}"}.join('')]
    end

# File net/http.rb, line 1435
    def set_form_data(params, sep = '&')
      self.body = params.map {|k,v| "#{urlencode(k.to_s)}=#{urlencode(v.to_s)}" }.join(sep)
      self.content_type = 'application/x-www-form-urlencoded'
    end

# File net/http.rb, line 1307
    def set_range(r, e = nil)
      unless r
        @header.delete 'range'
        return r
      end
      r = (r...r+e) if e
      case r
      when Numeric
        n = r.to_i
        rangestr = (n > 0 ? "0-#{n-1}" : "-#{-n}")
      when Range
        first = r.first
        last = r.last
        last -= 1 if r.exclude_end?
        if last == -1
          rangestr = (first > 0 ? "#{first}-" : "-#{-first}")
        else
          raise HTTPHeaderSyntaxError, 'range.first is negative' if first < 0
          raise HTTPHeaderSyntaxError, 'range.last is negative' if last < 0
          raise HTTPHeaderSyntaxError, 'must be .first < .last' if first > last
          rangestr = "#{first}-#{last}"
        end
      else
        raise TypeError, 'Range/Integer is required'
      end
      @header['range'] = ["bytes=#{rangestr}"]
      r
    end

# File net/http.rb, line 1401
    def sub_type
      return nil unless @header['content-type']
      main, sub = *self['Content-Type'].split(';').first.to_s.split('/')
      return nil unless sub
      sub.strip
    end

# File net/http.rb, line 1265
    def to_hash
      @header.dup
    end

# File net/http.rb, line 1410
    def type_params
      result = {}
      list = self['Content-Type'].to_s.split(';')
      list.shift
      list.each do |param|
        k, v = *param.split('=', 2)
        result[k.strip] = v.strip
      end
      result
    end