Having an optional<any> generates an unchecked cast

What happened?

Defining an object like this:

MyObject:
  fields:
    myfield: optional<any>

Results in the following Java code:

    @Generated("com.palantir.conjure.java.types.BeanBuilderGenerator")
    @JsonIgnoreProperties(ignoreUnknown = true)
    public static final class Builder {
        ...
        @JsonSetter("detail")
        public Builder detail(Optional<?> detail) {
            this.detail =
                    (Optional<Object>) Preconditions.checkNotNull(detail, "detail cannot be null");
            return this;
        }

        public Builder detail(Object detail) {
            this.detail = Optional.of(Preconditions.checkNotNull(detail, "detail cannot be null"));
            return this;
        }
    }

Where Optional<?> is cast into an Optional<Object>.

What did you want to happen?

    public static final class Builder {
        ...
        @JsonSetter("detail")
        public Builder detail(Optional<Object> detail) {
            this.detail = Preconditions.checkNotNull(detail, "detail cannot be null");
            return this;
        }
		...
    }

Start by locating the BeanBuilderGenerator named in the generated annotation and reproduce the optional example from the issue. Check the generated builder method for Optional<?> and verify that the result uses Optional without an unchecked cast; the Java output shown in the issue defines the expected behavior.