code: function getExistingConfigSources(sourceType) {
      const sources = new Set();
      try {
          const config = utils.loadConfig(true);
          for (const profile in config) {
              if (config[profile][sourceType]) {
                  sources.add(config[profile][sourceType]);
              }
          }
      } catch (ex) {
          // Swallow
      }
      return Array.from(sources);
  }
docs: If a swagen.config.json configuration file exists in the current directory, any existing Swagger
  sources for the specified source type (url or file) will be returned.
  @param {'url'|'file'} sourceType
  @returns {string[]} List of existing sources for the specified source type