DarkoHaxRP.java

package shadows.darkohax2;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import net.minecraftforge.fml.common.Mod;

@Mod(DarkoHaxRP.MODID)
public class DarkoHaxRP {

	public static final String MODID = "darkohax2";
	public static final Logger LOG = LogManager.getLogger(MODID);

}

MixinPipeBakedModel.java

package shadows.darkohax2.mixin;

import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.spongepowered.asm.mixin.Mixin;
import org.spongepowered.asm.mixin.Shadow;

import com.refinedmods.refinedpipes.render.PipeBakedModel;
import com.refinedmods.refinedpipes.render.PipeState;

import net.minecraft.client.renderer.model.BakedQuad;

@Mixin(PipeBakedModel.class)
public abstract class MixinPipeBakedModel {

	@Shadow(remap = false)
	private final Map<PipeState, List<BakedQuad>> cache = new ConcurrentHashMap<>();
}