code: function (file, importOptions = {}) {
          var self = this;
  
          // Step 1: Handle converting the file to usable data
          return this.loadFile(file).then(function (importData) {
              // Step 2: Let the importers pre-process the data
              return self.preProcess(importData);
          }).then(function (importData) {
              // Step 3: Actually do the import
              // @TODO: It would be cool to have some sort of dry run flag here
              return self.doImport(importData, importOptions);
          }).then(function (importData) {
              // Step 4: Report on the import
              return self.generateReport(importData);
          }).finally(() => self.cleanUp()); // Step 5: Cleanup any files
      }
docs: Import From File
  The main method of the ImportManager, call this to kick everything off!
  @param {File} file
  @param {importOptions} importOptions to allow override of certain import features such as locking a user
  @returns {Promise}