class Faraday::Request::Authorization

def self.build_hash(type, hash)
  comma = ', '
  values = []
  hash.each do |key, value|
    values << "#{key}=#{value.to_s.inspect}"
  end
  "#{type} #{values * comma}"
end

def self.header(type, token)
  case token
  when String, Symbol
    "#{type} #{token}"
  when Hash
    build_hash(type.to_s, token)
  else
    raise ArgumentError,
          "Can't build an Authorization #{type}" \
            "header from #{token.inspect}"
  end
end

def call(env)
  env.request_headers[KEY] = @header_value unless env.request_headers[KEY]
  @app.call(env)
end

def initialize(app, type, token)
  @header_value = self.class.header(type, token)
  super(app)
end