public ResourceLocation getLocation() {
        return new StringResourceLocation(displayName);
    }

    @Override
    public boolean getExists() {
        return true;
    }

    private static class StringResourceLocation implements ResourceLocation {
        private final String displayName;

        public StringResourceLocation(String displayName) {
            this.displayName = displayName;

Class <org.gradle.internal.resource.ResourceLocation> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (ResourceLocation.java:0)
Class <org.gradle.internal.resource.StringTextResource$StringResourceLocation> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (StringTextResource.java:0)