Method Error

package com.azrael.magus.handler;

import java.io.File;

import com.azrael.magus.reference.Reference;

import cpw.mods.fml.client.event.ConfigChangedEvent;
import cpw.mods.fml.common.eventhandler.SubscribeEvent;
import net.minecraftforge.common.config.Configuration;
import net.minecraftforge.common.config.Property;

public class ConfigurationHandler {

    public static Configuration configuration;
    public static boolean testValue = false;

    public static void init(File configFile){

        if(configuration == null){

         configuration = new Configuration(configFile);
        }
    }


    @SubscribeEvent
    public void onConfigurationChangedEvent(ConfigChangedEvent.OnConfigChangedEvent event){

        if(event.modID.equalsIgnoreCase(Reference.MOD_ID)){
            //resync config file
        }

    }

    public void loadConfiguration(){
        testValue = Configuration.getBoolean("configValue", Configuration.CATEGORY_GENERAL, false, "example config value");
    }
}