Android - ใครก็ไ้ด้ ช่วยอธิบาย การทำงาน ขอ class นี้แต่ละบรรทัดหน่อยครับ

 /***** Get Image Resource from URL (Start) *****/
    			private static final String TAG = "ERROR";
    			private static final int IO_BUFFER_SIZE = 4 * 1024;
    			
    			public static Bitmap loadBitmap(String url) {
    			    Bitmap bitmap = null;
    			    InputStream in = null;
    			    BufferedOutputStream out = null;

    			    try {
    			        in = new BufferedInputStream(new URL(url).openStream(), IO_BUFFER_SIZE);

    			        final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
    			        out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);
    			        copy(in, out);
    			        out.flush();

    			        final byte[] data = dataStream.toByteArray();
    			        BitmapFactory.Options options = new BitmapFactory.Options();
    			        //options.inSampleSize = 1;

    			        bitmap = BitmapFactory.decodeByteArray(data, 0, data.length,options);
    			    } catch (IOException e) {
    			        Log.e(TAG, "Could not load Bitmap from: " + url);
    			    } finally {
    			        closeStream(in);
    			        closeStream(out);
    			    }

    			    return bitmap;
    			}

    			 private static void closeStream(Closeable stream) {
    			        if (stream != null) {
    			            try {
    			                stream.close();
    			            } catch (IOException e) {
    			                android.util.Log.e(TAG, "Could not close stream", e);
    			            }
    			        }
    			    }
    			 
    			 private static void copy(InputStream in, OutputStream out) throws IOException {
    		        byte[] b = new byte[IO_BUFFER_SIZE];
    		        int read;
    		        while ((read = in.read(b)) != -1) {
    		            out.write(b, 0, read);
    		        }
    		    }