How to create mushroom in mcreator?

You can not create mushroom with using option in the new mod dialog!

You can create mushroom only using code!!!

Please write the code of this.

Please write the code of provided event 

Please edit this code 

import net.minecraftforge.fml.relauncher.SideOnly;
import net.minecraftforge.fml.relauncher.Side;
import net.minecraftforge.fml.common.registry.ForgeRegistries;
import net.minecraftforge.fml.common.event.FMLServerStartingEvent;
import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
import net.minecraftforge.fml.common.event.FMLInitializationEvent;

import net.minecraft.world.gen.feature.WorldGenFlowers;
import net.minecraft.world.World;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.NonNullList;
import net.minecraft.item.ItemStack;
import net.minecraft.item.ItemBlock;
import net.minecraft.item.Item;
import net.minecraft.creativetab.CreativeTabs;
import net.minecraft.client.renderer.block.model.ModelResourceLocation;
import net.minecraft.client.Minecraft;
import net.minecraft.block.state.IBlockState;
import net.minecraft.block.SoundType;
import net.minecraft.block.BlockFlower;
import net.minecraft.block.Block;

import java.util.Random;

public class mcreator_greenmushroom {

    public mcreator_greenmushroom() {
    }

    public static Block block;

    public static Object instance;

    public void generateNether(World world, Random random, int chunkX, int chunkZ) {
    }

    public int addFuel(ItemStack fuel) {
        return 0;
    }

    public void serverLoad(FMLServerStartingEvent event) {
    }

    public void preInit(FMLPreInitializationEvent event) {
        block = (Block) (new BlockCustomFlower()).setHardness(0.01F).setResistance(2.0F).setLightLevel(0.0F).setUnlocalizedName("greenmushroom");
        block.setRegistryName("greenmushroom");
        ForgeRegistries.BLOCKS.register(block);
        ForgeRegistries.ITEMS.register(new ItemBlock(block).setRegistryName(block.getRegistryName()));
    }

    public void registerRenderers() {
    }

    public void load(FMLInitializationEvent event) {
        if (event.getSide() == Side.CLIENT) {
            Minecraft.getMinecraft().getRenderItem().getItemModelMesher()
                    .register(Item.getItemFromBlock(block), 0, new ModelResourceLocation("testenvironmentmod:greenmushroom", "inventory"));
        }
    }

    public void generateSurface(World world, java.util.Random randomGenerator, int chunkX, int chunkZ) {
        for (int i = 0; i < 20; i++) {
            int l6 = chunkX + randomGenerator.nextInt(16) + 8;
            int i11 = randomGenerator.nextInt(128);
            int l14 = chunkZ + randomGenerator.nextInt(16) + 8;
            (new WorldGenFlowers(((BlockFlower) mcreator_greenmushroom.block), BlockFlower.EnumFlowerType.DANDELION)).generate(world,
                    randomGenerator, new BlockPos(l6, i11, l14));
        }
    }

    public static class BlockCustomFlower extends BlockFlower {

        public BlockCustomFlower() {
            super();
            setSoundType(SoundType.GROUND);

            this.setCreativeTab(CreativeTabs.DECORATIONS);
        }

        @Override
        public BlockFlower.EnumFlowerColor getBlockType() {
            return BlockFlower.EnumFlowerColor.YELLOW;
        }

        @SideOnly(Side.CLIENT)
        @SuppressWarnings("unchecked")
        @Override
        public void getSubBlocks(CreativeTabs tab, NonNullList<ItemStack> list) {
            for (BlockFlower.EnumFlowerType blockflower$enumflowertype : BlockFlower.EnumFlowerType.getTypes(this.getBlockType())) {
                list.add(new ItemStack(this, 1, blockflower$enumflowertype.getMeta()));
            }
        }

        @Override
        public int quantityDropped(Random par1Random) {
            return 1;
        }

        @Override
        public Item getItemDropped(IBlockState state, Random rand, int fortune) {
            return Item.getItemFromBlock(block);
        }
    }
}

no they should be placed on a tree on a stone and under a certain light (like conventional mushrooms)