我试图编码一个快速的应用程序，给我所需的3g值，当我点击一个按钮。但首先我需要检查我是否连接到3g网络。但是我的权限有一些问题。我有以下代码：

public void calculate(View view) {
    TextView rscp = (TextView) findViewById(R.id.RSCP);
    TextView rssi = (TextView) findViewById(R.id.RSSI);
    TextView ecno = (TextView) findViewById(R.id.EcNo);
    TelephonyManager tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
    if (Arrays.stream(values_3G).anyMatch(n -> n == tm.getDataNetworkType())) {
        for (CellInfo cellInfo : tm.getAllCellInfo()) {
            if (cellInfo instanceof CellInfoWcdma) {
                CellSignalStrengthWcdma cellSignalStrength = ((CellInfoWcdma) cellInfo).getCellSignalStrength();
                rscp.setText(cellSignalStrength.getDbm());
                ecno.setText(cellSignalStrength.getEcNo());
                int rssiValue = -113 + 2 * cellSignalStrength.getAsuLevel();
                rssi.setText(rssiValue);
            }
        }
    } else {
        rscp.setText(0);
        rssi.setText(0);
        ecno.setText(0);
        Log.i(TAG, "No 3G Mobile connection detected!");
        Toast.makeText(getApplicationContext(), "Connect to 3G", Toast.LENGTH_SHORT).show();

    }

}
``` `tm.getDataNetworkType()` 正在给我以下关于read\u phone\u state的问题：

Call requires permission which may be rejected by user: code should explicitly check to see if permission is available (with checkPermission) or explicitly handle a potential SecurityException

如果我按照说明在android studio中检查权限，我会得到以下结果：

if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}

我需要在括号里填什么？