my elephant wont work can you tell me why

my elephant wont work so if you could help me that would be great.

// Made with Blockbench 4.0.2
// Exported for Minecraft version 1.15 - 1.16 with Mojang mappings
// Paste this class into your mod and generate all required imports


public class custom_model extends EntityModel<Entity> {
	private final ModelRenderer frfeet;
	private final ModelRenderer blfeet;
	private final ModelRenderer brfeet;
	private final ModelRenderer flfeet;
	private final ModelRenderer body;
	private final ModelRenderer head;
	private final ModelRenderer rear;
	private final ModelRenderer cube_r1;
	private final ModelRenderer lear;
	private final ModelRenderer cube_r2;
	private final ModelRenderer trunk;
	private final ModelRenderer cube_r3;
	private final ModelRenderer cube_r4;
	private final ModelRenderer tail;
	private final ModelRenderer cube_r5;

	public custom_model() {
		texWidth = 64;
		texHeight = 64;

		frfeet = new ModelRenderer(this);
		frfeet.setPos(0.0F, 24.0F, 3.0F);
		frfeet.texOffs(15, 14).addBox(-4.0F, -2.0F, -5.0F, 1.0F, 2.0F, 1.0F, 0.0F, false);

		blfeet = new ModelRenderer(this);
		blfeet.setPos(0.0F, 24.0F, 3.0F);
		blfeet.texOffs(4, 6).addBox(2.0F, -2.0F, 3.0F, 1.0F, 2.0F, 1.0F, 0.0F, false);

		brfeet = new ModelRenderer(this);
		brfeet.setPos(0.0F, 24.0F, 3.0F);
		brfeet.texOffs(0, 6).addBox(-4.0F, -2.0F, 3.0F, 1.0F, 2.0F, 1.0F, 0.0F, false);

		flfeet = new ModelRenderer(this);
		flfeet.setPos(0.0F, 24.0F, 0.0F);
		flfeet.texOffs(0, 14).addBox(2.0F, -2.0F, -2.0F, 1.0F, 2.0F, 1.0F, 0.0F, false);

		body = new ModelRenderer(this);
		body.setPos(0.0F, 24.0F, 0.0F);
		body.texOffs(0, 0).addBox(-4.0F, -7.0F, -2.0F, 7.0F, 5.0F, 9.0F, 0.0F, false);

		head = new ModelRenderer(this);
		head.setPos(0.0F, 24.0F, 0.0F);
		head.texOffs(0, 14).addBox(-3.0F, -12.0F, -6.0F, 5.0F, 5.0F, 5.0F, 0.0F, false);

		rear = new ModelRenderer(this);
		rear.setPos(-3.0F, 12.0F, -3.0F);
		

		cube_r1 = new ModelRenderer(this);
		cube_r1.setPos(0.0F, 0.0F, 0.0F);
		rear.addChild(cube_r1);
		setRotationAngle(cube_r1, 0.0F, 0.0F, 0.6545F);
		cube_r1.texOffs(15, 19).addBox(0.0F, 0.0F, -3.0F, 1.0F, 4.0F, 5.0F, 0.0F, false);

		lear = new ModelRenderer(this);
		lear.setPos(0.0F, 24.0F, 0.0F);
		

		cube_r2 = new ModelRenderer(this);
		cube_r2.setPos(2.0F, -12.0F, -3.0F);
		lear.addChild(cube_r2);
		setRotationAngle(cube_r2, 0.0F, 0.0F, -0.6545F);
		cube_r2.texOffs(22, 14).addBox(-1.0F, 0.0F, -3.0F, 1.0F, 4.0F, 5.0F, 0.0F, false);

		trunk = new ModelRenderer(this);
		trunk.setPos(0.0F, 24.0F, 0.0F);
		trunk.texOffs(0, 17).addBox(-1.0F, -9.0F, -7.0F, 1.0F, 1.0F, 1.0F, 0.0F, false);

		cube_r3 = new ModelRenderer(this);
		cube_r3.setPos(0.0F, -8.0F, -7.0F);
		trunk.addChild(cube_r3);
		setRotationAngle(cube_r3, -0.3054F, 0.0F, 0.0F);
		cube_r3.texOffs(4, 0).addBox(-1.0F, 1.0F, -1.0F, 1.0F, 2.0F, 1.0F, 0.0F, false);

		cube_r4 = new ModelRenderer(this);
		cube_r4.setPos(-1.0F, -9.0F, -7.0F);
		trunk.addChild(cube_r4);
		setRotationAngle(cube_r4, 0.9163F, 0.0F, 0.0F);
		cube_r4.texOffs(2, 3).addBox(0.0F, 0.0F, -2.0F, 1.0F, 1.0F, 2.0F, 0.0F, false);

		tail = new ModelRenderer(this);
		tail.setPos(0.0F, 24.0F, 0.0F);
		

		cube_r5 = new ModelRenderer(this);
		cube_r5.setPos(0.0F, -6.0F, 7.0F);
		tail.addChild(cube_r5);
		setRotationAngle(cube_r5, 0.3927F, 0.0F, 0.0F);
		cube_r5.texOffs(0, 0).addBox(-1.0F, 0.0F, -1.0F, 1.0F, 4.0F, 1.0F, 0.0F, false);
	}

	@Override
	public void setupAnim(Entity entity, float limbSwing, float limbSwingAmount, float ageInTicks, float netHeadYaw, float headPitch){
		//previously the render function, render code was moved to a method below
	}

	@Override
	public void renderToBuffer(MatrixStack matrixStack, IVertexBuilder buffer, int packedLight, int packedOverlay, float red, float green, float blue, float alpha){
		frfeet.render(matrixStack, buffer, packedLight, packedOverlay);
		blfeet.render(matrixStack, buffer, packedLight, packedOverlay);
		brfeet.render(matrixStack, buffer, packedLight, packedOverlay);
		flfeet.render(matrixStack, buffer, packedLight, packedOverlay);
		body.render(matrixStack, buffer, packedLight, packedOverlay);
		head.render(matrixStack, buffer, packedLight, packedOverlay);
		rear.render(matrixStack, buffer, packedLight, packedOverlay);
		lear.render(matrixStack, buffer, packedLight, packedOverlay);
		trunk.render(matrixStack, buffer, packedLight, packedOverlay);
		tail.render(matrixStack, buffer, packedLight, packedOverlay);
	}

	public void setRotationAngle(ModelRenderer modelRenderer, float x, float y, float z) {
		modelRenderer.xRot = x;
		modelRenderer.yRot = y;
		modelRenderer.zRot = z;
	}
}