code: function appendParamsFromHeaders(params: Object, headers: Object): Object {
    if (!headers.values) {
      return undefined;
    }
  
    forOwn(headers.values, (value, key) => {
  
      const paramKey = HEADERS_TO_PARAMS_MAP[key];
      if (!paramKey) {
        // TODO: Dedicated error
        throw new Error(`File option "headers.${key}" is not supported by S3`);
      }
  
      params[paramKey] = value;
    });
  
    return params;
  }
docs: Append S3 headers params.
  
  @static
  @private
  @param params
  @param headers
  @returns Params.