code: public static PluginSpec readPluginSpecFile(URL pluginSpec) throws IOException {
          return (PluginSpec) mapper.reader(PluginSpec.class).readValue(pluginSpec);
      }
docs: Reads a plugin spec file and returns a {@link PluginSpec}.
  @param pluginSpec the plugin spec
  @throws IOException when an unhandled exception occurs
  @return plugin's specification