def expand_header(header = {})
      header = DEFAULT_HEADER.merge(header)
      header['X-ITRP-Account'] = option(:account) if option(:account)
      header['AUTHORIZATION'] = 'Basic ' + ["#{option(:api_token)}:x"].pack('m*').gsub(/\s/, '')
      if option(:source)
        header['X-ITRP-Source'] = option(:source)
        header['HTTP_USER_AGENT'] = option(:source)
      end
      header
    end
def expand_header(header = {})
      header = DEFAULT_HEADER.merge(header)
      header['X-ITRP-Account'] = option(:account) if option(:account)
      header['AUTHORIZATION'] = 'Basic ' + ["#{option(:api_token)}:x"].pack('m*').gsub(/\s/, '')
      if option(:source)
        header['X-ITRP-Source'] = option(:source)
        header['HTTP_USER_AGENT'] = option(:source)
      end
      header
    end
Expand the given header with the default header