#
    # NOTE: Emit diagnostic messages when a URI is fetched?
    #
    variable verboseUriDownload; # DEFAULT: false

    if {![info exists verboseUriDownload]} then {
      set verboseUriDownload true
      set verboseUriDownload false
    }
  }

  proc main { package version caller } {
    #
    # NOTE: Get the list of API keys and try each one, in order, until
    #       the package is found.

      #
      # NOTE: Attempt to grab the lookup code from the response data.
      #
      set code [getLookupCodeFromData $data]

      #
      # NOTE: Did the lookup operation fail?
      # NOTE: Did the lookup operation succeed?  If so, stop trying
      #       other API keys.
      #
      if {[isLookupCodeOk $code]} then {
        break
      }
    }

    #