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/*
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* Copyright (C) 2012 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.example.android.displayingbitmaps.ui;
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import android.annotation.TargetApi;
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import android.app.ActionBar;
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import android.os.Build.VERSION_CODES;
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import android.os.Bundle;
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import android.support.v4.app.Fragment;
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import android.support.v4.app.FragmentActivity;
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import android.support.v4.app.FragmentManager;
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import android.support.v4.app.FragmentStatePagerAdapter;
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import android.support.v4.app.NavUtils;
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import android.support.v4.view.ViewPager;
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import android.util.DisplayMetrics;
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import android.view.Menu;
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import android.view.MenuItem;
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import android.view.View;
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import android.view.View.OnClickListener;
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import android.view.WindowManager.LayoutParams;
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import android.widget.Toast;
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import com.example.android.displayingbitmaps.BuildConfig;
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import com.example.android.displayingbitmaps.R;
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import com.example.android.displayingbitmaps.provider.Images;
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import com.example.android.displayingbitmaps.util.ImageCache;
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import com.example.android.displayingbitmaps.util.ImageFetcher;
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import com.example.android.displayingbitmaps.util.Utils;
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public class ImageDetailActivity extends FragmentActivity implements OnClickListener {
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private static final String IMAGE_CACHE_DIR = "images";
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public static final String EXTRA_IMAGE = "extra_image";
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private ImagePagerAdapter mAdapter;
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private ImageFetcher mImageFetcher;
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private ViewPager mPager;
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@TargetApi(VERSION_CODES.HONEYCOMB)
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@Override
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public void onCreate(Bundle savedInstanceState) {
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if (BuildConfig.DEBUG) {
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Utils.enableStrictMode();
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}
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super.onCreate(savedInstanceState);
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setContentView(R.layout.image_detail_pager);
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// Fetch screen height and width, to use as our max size when loading images as this
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// activity runs full screen
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final DisplayMetrics displayMetrics = new DisplayMetrics();
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getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
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final int height = displayMetrics.heightPixels;
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final int width = displayMetrics.widthPixels;
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// For this sample we'll use half of the longest width to resize our images. As the
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// image scaling ensures the image is larger than this, we should be left with a
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// resolution that is appropriate for both portrait and landscape. For best image quality
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// we shouldn't divide by 2, but this will use more memory and require a larger memory
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// cache.
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final int longest = (height > width ? height : width) / 2;
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ImageCache.ImageCacheParams cacheParams =
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new ImageCache.ImageCacheParams(this, IMAGE_CACHE_DIR);
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cacheParams.setMemCacheSizePercent(0.25f); // Set memory cache to 25% of app memory
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// The ImageFetcher takes care of loading images into our ImageView children asynchronously
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mImageFetcher = new ImageFetcher(this, longest);
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mImageFetcher.addImageCache(getSupportFragmentManager(), cacheParams);
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mImageFetcher.setImageFadeIn(false);
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// Set up ViewPager and backing adapter
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mAdapter = new ImagePagerAdapter(getSupportFragmentManager(), Images.imageUrls.length);
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mPager = (ViewPager) findViewById(R.id.pager);
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mPager.setAdapter(mAdapter);
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mPager.setPageMargin((int) getResources().getDimension(R.dimen.horizontal_page_margin));
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mPager.setOffscreenPageLimit(2);
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// Set up activity to go full screen
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getWindow().addFlags(LayoutParams.FLAG_FULLSCREEN);
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// Enable some additional newer visibility and ActionBar features to create a more
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// immersive photo viewing experience
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if (Utils.hasHoneycomb()) {
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final ActionBar actionBar = getActionBar();
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// Hide title text and set home as up
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actionBar.setDisplayShowTitleEnabled(false);
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actionBar.setDisplayHomeAsUpEnabled(true);
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// Hide and show the ActionBar as the visibility changes
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mPager.setOnSystemUiVisibilityChangeListener(
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new View.OnSystemUiVisibilityChangeListener() {
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@Override
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public void onSystemUiVisibilityChange(int vis) {
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if ((vis & View.SYSTEM_UI_FLAG_LOW_PROFILE) != 0) {
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actionBar.hide();
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} else {
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actionBar.show();
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}
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}
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});
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// Start low profile mode and hide ActionBar
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mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);
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actionBar.hide();
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}
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// Set the current item based on the extra passed in to this activity
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final int extraCurrentItem = getIntent().getIntExtra(EXTRA_IMAGE, -1);
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if (extraCurrentItem != -1) {
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mPager.setCurrentItem(extraCurrentItem);
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}
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}
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@Override
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public void onResume() {
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super.onResume();
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mImageFetcher.setExitTasksEarly(false);
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}
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@Override
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protected void onPause() {
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super.onPause();
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mImageFetcher.setExitTasksEarly(true);
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mImageFetcher.flushCache();
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}
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@Override
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protected void onDestroy() {
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super.onDestroy();
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mImageFetcher.closeCache();
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}
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@Override
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public boolean onOptionsItemSelected(MenuItem item) {
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switch (item.getItemId()) {
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case android.R.id.home:
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NavUtils.navigateUpFromSameTask(this);
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return true;
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case R.id.clear_cache:
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mImageFetcher.clearCache();
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Toast.makeText(
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this, R.string.clear_cache_complete_toast,Toast.LENGTH_SHORT).show();
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return true;
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}
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return super.onOptionsItemSelected(item);
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}
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@Override
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public boolean onCreateOptionsMenu(Menu menu) {
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getMenuInflater().inflate(R.menu.main_menu, menu);
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return true;
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}
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/**
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* Called by the ViewPager child fragments to load images via the one ImageFetcher
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*/
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public ImageFetcher getImageFetcher() {
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return mImageFetcher;
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}
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/**
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* The main adapter that backs the ViewPager. A subclass of FragmentStatePagerAdapter as there
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* could be a large number of items in the ViewPager and we don't want to retain them all in
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* memory at once but create/destroy them on the fly.
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*/
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private class ImagePagerAdapter extends FragmentStatePagerAdapter {
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private final int mSize;
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public ImagePagerAdapter(FragmentManager fm, int size) {
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super(fm);
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mSize = size;
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}
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@Override
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public int getCount() {
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return mSize;
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}
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@Override
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public Fragment getItem(int position) {
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return ImageDetailFragment.newInstance(Images.imageUrls[position]);
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}
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}
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/**
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* Set on the ImageView in the ViewPager children fragments, to enable/disable low profile mode
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* when the ImageView is touched.
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*/
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@TargetApi(VERSION_CODES.HONEYCOMB)
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@Override
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public void onClick(View v) {
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final int vis = mPager.getSystemUiVisibility();
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if ((vis & View.SYSTEM_UI_FLAG_LOW_PROFILE) != 0) {
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mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_VISIBLE);
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} else {
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mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);
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}
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}
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}