Method append

Libraries/Network/FormData.js:55–62

(key: string, value: FormDataValue)

  }

  append(key: string, value: FormDataValue) {
    // The XMLHttpRequest spec doesn't specify if duplicate keys are allowed.
    // MDN says that any new values should be appended to existing values.
    // In any case, major browsers allow duplicate keys, so that's what we'll do
    // too. They'll simply get appended as additional form data parts in the
    // request body, leaving the server to deal with them.
    this._parts.push([key, value]);
  }

  getParts(): Array<FormDataPart> {
    return this._parts.map(([name, value]) => {