private Supplier<JsonNode> returnMinimumNumericValue(List<JsonNode> nodes) {
        if (nodes.stream().allMatch(JsonNode::isNumber)) {
            return () -> nodes.stream().reduce((a, b) -> a.asDouble() < b.asDouble() ? a : b).orElse(null);
        }
        return null;
    }
Check whether the merging of the given node and it's allOf entries should be skipped due to a {@link SchemaKeyword#TAG_REF} being present.
Drafts 6 and 7 would ignore any other attributes besides the {@link SchemaKeyword#TAG_REF}.

@param mainNode the main node containing an {@link SchemaKeyword#TAG_ALLOF} array (maybe {@code null})
@param parts entries of the {@link SchemaKeyword#TAG_ALLOF} array to consider
@param fieldsFromAllParts flattened collection of all attributes in the given parts
@return whether to block merging of the given {@link SchemaKeyword#TAG_ALLOF} candidate
jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/impl/SchemaCleanUpUtils.java