Replace stream().min() to Collections.min() to avoid stream object.

import java.util.ArrayList;

import java.util.Calendar;

import java.util.Collections;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

            return null;

        }

        final long rawStartTimestamp =

                batteryHistoryMap.keySet().stream().min(Long::compare).orElse(0L);

        final long rawStartTimestamp = Collections.min(batteryHistoryMap.keySet());

        // Start the async task to compute diff usage data and load labels and icons.

        new DataProcessManager(

                context,