Add BluetoothHeadsetClientCall.toString method

        return mOutgoing;

    }

    public String toString() {

        StringBuilder builder = new StringBuilder("BluetoothHeadsetClientCall{mId: ");

        builder.append(mId);

        builder.append(", mState: ");

        switch (mState) {

            case CALL_STATE_ACTIVE: builder.append("ACTIVE"); break;

            case CALL_STATE_HELD: builder.append("HELD"); break;

            case CALL_STATE_DIALING: builder.append("DIALING"); break;

            case CALL_STATE_ALERTING: builder.append("ALERTING"); break;

            case CALL_STATE_INCOMING: builder.append("INCOMING"); break;

            case CALL_STATE_WAITING: builder.append("WAITING"); break;

            case CALL_STATE_HELD_BY_RESPONSE_AND_HOLD: builder.append("HELD_BY_RESPONSE_AND_HOLD"); break;

            case CALL_STATE_TERMINATED: builder.append("TERMINATED"); break;

            default: builder.append(mState); break;

        }

        builder.append(", mNumber: ");

        builder.append(mNumber);

        builder.append(", mMultiParty: ");

        builder.append(mMultiParty);

        builder.append(", mOutgoing: ");

        builder.append(mOutgoing);

        builder.append("}");

        return builder.toString();

    }

    /**

     * {@link Parcelable.Creator} interface implementation.

     */