Cache flag values when they are read.

import org.json.JSONException;

import org.json.JSONObject;

import java.util.HashMap;

import java.util.Map;

import javax.inject.Inject;

    private static final String FLAGS_PERMISSION = "com.android.systemui.permission.FLAGS";

    private final SystemPropertiesHelper mSystemPropertiesHelper;

    private final Map<Integer, Boolean> mBooleanFlagCache = new HashMap<>();

    @Inject

    public FeatureFlagManager(SystemPropertiesHelper systemPropertiesHelper, Context context) {

        mSystemPropertiesHelper = systemPropertiesHelper;

    /** Return a {@link BooleanFlag}'s value. */

    public boolean isEnabled(int id, boolean defaultValue) {

        if (!mBooleanFlagCache.containsKey(id)) {

            Boolean result = isEnabledInternal(id);

        return result == null ? defaultValue : result;

            mBooleanFlagCache.put(id, result == null ? defaultValue : result);

        }

        return mBooleanFlagCache.get(id);

    }

    /** Returns the stored value or null if not set. */