[1.15.2] Trouble implementing simple capabilities (ICapabilitySerializable cannot be resolved to a type)

[Delupara]

The title says it all, The docs says "if the capability needs to store data persistently it is possible to implement ICapabilitySerializable<T extends NBTBase>". I tried yet ICapabilitySerializable is not valid. I think either my setup is broken or the docs are outdated.

 

Relevant classes:

MemeStorage.java

Spoiler

package com.delupara.dankmemes.capabilities;

import net.minecraft.nbt.CompoundNBT;
import net.minecraft.nbt.INBT;
import net.minecraft.util.Direction;
import net.minecraftforge.common.capabilities.Capability;
import net.minecraftforge.common.capabilities.Capability.IStorage;

public class MemeStorage implements IStorage<IMeme>{

	@Override
	public INBT writeNBT(Capability<IMeme> capability, IMeme instance, Direction side) {
		// TODO Auto-generated method stub
		CompoundNBT tag = new CompoundNBT();
		tag.putInt("Meme Points", instance.getMemePoints());
		return tag;
	}

	@Override
	public void readNBT(Capability<IMeme> capability, IMeme instance, Direction side, INBT nbt) {
		CompoundNBT tag = (CompoundNBT) nbt;
		instance.setMemePoints(tag.getInt("Meme Points"));
	}
	
}

 

Meme.java
 

Spoiler

package com.delupara.dankmemes;

import com.delupara.dankmemes.capabilities.IMemeLevel;

public class Meme extends DankItem implements IMemeLevel {

	private int points;
	
	private int NextLevel;
	
	private int Level;
	
	
	public Meme(Properties properties, String name) {
		super(properties, name);
		}


	@Override
	public int getMemePoints() {
		// TODO Auto-generated method stub
		return points;
	}


	@Override
	public void setMemePoints(int amount) {
		// TODO Auto-generated method stub
		points = amount;
	}


	@Override
	public int getNextLevel(int PreviousLevelCap) {
		return PreviousLevelCap*2;
	}

	@Override
	public void LevelUp() {
		Level += 1;
		NextLevel = getNextLevel(NextLevel);
	}

}

 

 IMeme.java
 

Spoiler

package com.delupara.dankmemes.capabilities;

public interface IMeme 
{
	int getMemePoints();
	void setMemePoints(int amount);
	
}

 

 

MemeProvider.java (Where I'm trying to extend ICapabilitySerializable<CompoundNBT>) has no lines except a blank constructor. The error is in the title. Please help.

Edited April 28, 2020 by Delupara
Mistake