code: function (params) {
      var url = 'https://content.dropboxapi.com/2/files/upload';
      var args = {
        path: getDropboxPath(params.path),
        mode: {'.tag': 'overwrite'},
        mute: true
      };
  
      if (params.ifMatch) {
        args.mode = {'.tag': 'update', update: params.ifMatch};
      }
  
      return this._request('POST', url, {
        body: params.body,
        headers: {
          'Content-Type': 'application/octet-stream',
          'Dropbox-API-Arg': JSON.stringify(args)
        }
      }).then((response) => {
        if (response.status !== 200 && response.status !== 409) {
          return Promise.resolve({statusCode: response.status});
        }
  
        var body = response.responseText;
  
        try {
          body = JSON.parse(body);
        } catch (e) {
          return Promise.reject(new Error('Invalid API result: ' + body));
        }
  
        if (response.status === 409) {
          if (compareApiError(body, ['path', 'conflict'])) {
            return this._getMetadata(params.path).then(function (metadata) {
              return Promise.resolve({
                statusCode: 412,
                revision: metadata.rev
              });
            });
          }
          return Promise.reject(new Error('API error: ' + body.error_summary));
        }
  
        this._revCache.set(params.path, body.rev);
  
        return Promise.resolve({ statusCode: response.status, revision: body.rev });
      });
    }
docs: Upload a simple file (the size is no more than 150MB).
  
  @param {Object} params
  @param {string} options.ifMatch - Only update the file if its ETag
  matches this string
  @param {string} options.path - path of the file
  @param {string} options.body - contents of the file to upload
  @param {string} options.contentType - mime type of the file
  
  @return {Promise} A promise for an object with the following structure:
  statusCode - HTTP status code
  revision - revision of the newly-created file, if any
  
  @private