code: public static Intent newCallNumberIntent(String phoneNumber) {
          final Intent intent;
          if (phoneNumber == null || phoneNumber.trim().length() <= 0) {
              intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:"));
          } else {
              intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + phoneNumber.replace(" ", "")));
          }
          return intent;
      }
docs: Creates an intent that will immediately dispatch a call to the given number. NOTE that unlike
  {@link #newDialNumberIntent(String)}, this intent requires the {@link android.Manifest.permission#CALL_PHONE}
  permission to be set.
  
  @param phoneNumber the number to call
  @return the intent