For some reason when I put 'NameValuePair' it says cannot resolve symbol. How do I resolve this?

For some reason when I put 'NameValuePair' it says cannot resolve symbol. How do I resolve this?

The code:

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private static final int RESULT_LOAD_IMAGE = 1;

   ImageView imageToUpload, downloadedImage;
    Button bUploadImage, bDownloadImage;
    EditText uploadImageName, downloadImageName;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageToUpload = (ImageView) findViewById(R.id.imageToUpload);
        downloadedImage = (ImageView) findViewById(R.id.downloadedImage);

        bUploadImage = (Button) findViewById(R.id.bUploadImage);
        bDownloadImage = (Button) findViewById(R.id.bDownloadImage);

        uploadImageName = (EditText) findViewById(R.id.etUploadName);
        downloadImageName = (EditText) findViewById(R.id.etDownloadName);

        imageToUpload.setOnClickListener(this);
        bUploadImage.setOnClickListener(this);
        bDownloadImage.setOnClickListener(this);




}


    @Override
    public void onClick(View v) {
        switch(v.getId()){
            case R.id.imageToUpload:
                Intent galleryIntent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                startActivityForResult(galleryIntent, RESULT_LOAD_IMAGE);
                break;
            case R.id.bUploadImage:
                Bitmap Image = ((BitmapDrawable) imageToUpload.getDrawable()).getBitmap();




                break;
            case R.id.bDownloadImage:

                break;

        }


    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == RESULT_LOAD_IMAGE && resultCode ==RESULT_OK && data != null) {
            Uri selectedImage = data.getData();
            imageToUpload.setImageURI(selectedImage);
        }

        }

        private class UploadImage extends AsyncTask<Void, Void, Void>{

            Bitmap image;
            String name;

            public  UploadImage(Bitmap image, String name) {
                this.image = image;
                this.name = name;
            }

            @Override
            protected void onPostExecute(Void aVoid) {

                super.onPostExecute(aVoid);
            }

            @Override
            protected Void doInBackground(Void... params) {
                ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
                image.compress(Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream);
                String encodedImage = Base64.encodeToString(byteArrayOutputStream.toByteArray(), Base64.DEFAULT);

                ArrayList<NameValuePair> dataToSend = new ArrayList<>();
                dataToSend.add(new BasicNameValuePair("image"));


                return null;
            }
        }

    }

How do I solve the error of the 'NameValuePair'? Help will be appreciated in solving this error.

Thankyou