[Bluetooth] Android BluetoothAdapter

/**
 * Represents the local device Bluetooth adapter. The {@link BluetoothAdapter}
 * lets you perform fundamental Bluetooth tasks, such as initiate
 * device discovery, query a list of bonded (paired) devices,
 * instantiate a {@link BluetoothDevice} using a known MAC address, and create
 * a {@link BluetoothServerSocket} to listen for connection requests from other
 * devices.
 *
 * <p>To get a {@link BluetoothAdapter} representing the local Bluetooth
 * adapter, call the static {@link #getDefaultAdapter} method.
 * Fundamentally, this is your starting point for all
 * Bluetooth actions. Once you have the local adapter, you can get a set of
 * {@link BluetoothDevice} objects representing all paired devices with
 * {@link #getBondedDevices()}; start device discovery with
 * {@link #startDiscovery()}; or create a {@link BluetoothServerSocket} to
 * listen for incoming connection requests with
 * {@link #listenUsingRfcommWithServiceRecord(String,UUID)}.
 *
 * <p class="note"><strong>Note:</strong>
 * Most methods require the {@link android.Manifest.permission#BLUETOOTH}
 * permission and some also require the
 * {@link android.Manifest.permission#BLUETOOTH_ADMIN} permission.
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 * <p>For more information about using Bluetooth, read the
 * <a href="{@docRoot}guide/topics/wireless/bluetooth.html">Bluetooth</a> developer guide.</p>
 * </div>
 *
 * {@see BluetoothDevice}
 * {@see BluetoothServerSocket}
 */