Invalid model name Your model name is not a valid Java name!

Been looking at forums for hours and trying to fix it myself on blockbench but I cant figure it out. any one have any ideas? 

(Here's the model code)

// Made with Blockbench 4.8.3
// Exported for Minecraft version 1.17 or later with Mojang mappings
// Paste this class into your mod and generate all required imports

public class custom_model<T extends Entity> extends EntityModel<T> {
    // This layer location should be baked with EntityRendererProvider.Context in the entity renderer and passed into this model's constructor
    public static final ModelLayerLocation LAYER_LOCATION = new ModelLayerLocation(new ResourceLocation("modid", "custom_model"), "main");
    private final ModelPart Head;
    private final ModelPart Body;
    private final ModelPart RightArm;
    private final ModelPart LeftArm;
    private final ModelPart RightLeg;
    private final ModelPart LeftLeg;

    public custom_model(ModelPart root) {
        this.Head = root.getChild("Head");
        this.Body = root.getChild("Body");
        this.RightArm = root.getChild("RightArm");
        this.LeftArm = root.getChild("LeftArm");
        this.RightLeg = root.getChild("RightLeg");
        this.LeftLeg = root.getChild("LeftLeg");
    }

    public static LayerDefinition createBodyLayer() {
        MeshDefinition meshdefinition = new MeshDefinition();
        PartDefinition partdefinition = meshdefinition.getRoot();

        PartDefinition Head = partdefinition.addOrReplaceChild("Head", CubeListBuilder.create().texOffs(0, 0).addBox(-4.0F, -8.0F, -4.0F, 8.0F, 8.0F, 8.0F, new CubeDeformation(0.0F))
        .texOffs(32, 0).addBox(-4.0F, -8.0F, -4.0F, 8.0F, 8.0F, 8.0F, new CubeDeformation(0.5F)), PartPose.offsetAndRotation(0.0F, 0.0F, 0.0F, -0.1047F, 0.0873F, 0.0F));

        PartDefinition Body = partdefinition.addOrReplaceChild("Body", CubeListBuilder.create().texOffs(16, 16).addBox(-4.0F, 0.0F, -2.0F, 8.0F, 12.0F, 4.0F, new CubeDeformation(0.0F))
        .texOffs(16, 32).addBox(-4.0F, 0.0F, -2.0F, 8.0F, 12.0F, 4.0F, new CubeDeformation(0.25F)), PartPose.offset(0.0F, 0.0F, 0.0F));

        PartDefinition RightArm = partdefinition.addOrReplaceChild("RightArm", CubeListBuilder.create().texOffs(40, 16).addBox(-3.0F, -2.0F, -2.0F, 4.0F, 12.0F, 4.0F, new CubeDeformation(0.0F))
        .texOffs(40, 32).addBox(-3.0F, -2.0F, -2.0F, 4.0F, 12.0F, 4.0F, new CubeDeformation(0.25F)), PartPose.offsetAndRotation(-5.0F, 2.0F, 0.0F, -0.1745F, 0.0F, 0.0F));

        PartDefinition LeftArm = partdefinition.addOrReplaceChild("LeftArm", CubeListBuilder.create().texOffs(32, 48).addBox(-1.0F, -2.0F, -2.0F, 4.0F, 12.0F, 4.0F, new CubeDeformation(0.0F))
        .texOffs(48, 48).addBox(-1.0F, -2.0F, -2.0F, 4.0F, 12.0F, 4.0F, new CubeDeformation(0.25F)), PartPose.offsetAndRotation(5.0F, 2.0F, 0.0F, 0.2094F, 0.0F, 0.0F));

        PartDefinition RightLeg = partdefinition.addOrReplaceChild("RightLeg", CubeListBuilder.create().texOffs(0, 16).addBox(-2.0F, 0.0F, -2.0F, 4.0F, 12.0F, 4.0F, new CubeDeformation(0.0F))
        .texOffs(0, 32).addBox(-2.0F, 0.0F, -2.0F, 4.0F, 12.0F, 4.0F, new CubeDeformation(0.25F)), PartPose.offsetAndRotation(-1.9F, 12.0F, 0.0F, 0.192F, 0.0F, 0.0349F));

        PartDefinition LeftLeg = partdefinition.addOrReplaceChild("LeftLeg", CubeListBuilder.create().texOffs(16, 48).addBox(-2.0F, 0.0F, -2.0F, 4.0F, 12.0F, 4.0F, new CubeDeformation(0.0F))
        .texOffs(0, 48).addBox(-2.0F, 0.0F, -2.0F, 4.0F, 12.0F, 4.0F, new CubeDeformation(0.25F)), PartPose.offsetAndRotation(1.9F, 12.0F, 0.0F, -0.1745F, 0.0F, -0.0349F));

        return LayerDefinition.create(meshdefinition, 64, 64);
    }

    @Override
    public void setupAnim(T entity, float limbSwing, float limbSwingAmount, float ageInTicks, float netHeadYaw, float headPitch) {

    }

    @Override
    public void renderToBuffer(PoseStack poseStack, VertexConsumer vertexConsumer, int packedLight, int packedOverlay, float red, float green, float blue, float alpha) {
        Head.render(poseStack, vertexConsumer, packedLight, packedOverlay, red, green, blue, alpha);
        Body.render(poseStack, vertexConsumer, packedLight, packedOverlay, red, green, blue, alpha);
        RightArm.render(poseStack, vertexConsumer, packedLight, packedOverlay, red, green, blue, alpha);
        LeftArm.render(poseStack, vertexConsumer, packedLight, packedOverlay, red, green, blue, alpha);
        RightLeg.render(poseStack, vertexConsumer, packedLight, packedOverlay, red, green, blue, alpha);
        LeftLeg.render(poseStack, vertexConsumer, packedLight, packedOverlay, red, green, blue, alpha);
    }
}