internal static DocumentKeyValuePair DeserializeDocumentKeyValuePair(JsonElement element)
        {
            DocumentKeyValueElement            key   = default;
            Optional <DocumentKeyValueElement> value = default;
            float confidence = default;

            foreach (var property in element.EnumerateObject())
            {
                if (property.NameEquals("key"))
                {
                    key = DocumentKeyValueElement.DeserializeDocumentKeyValueElement(property.Value);
                    continue;
                }
                if (property.NameEquals("value"))
                {
                    if (property.Value.ValueKind == JsonValueKind.Null)
                    {
                        property.ThrowNonNullablePropertyIsNull();
                        continue;
                    }
                    value = DocumentKeyValueElement.DeserializeDocumentKeyValueElement(property.Value);
                    continue;
                }
                if (property.NameEquals("confidence"))
                {
                    confidence = property.Value.GetSingle();
                    continue;
                }
            }
            return(new DocumentKeyValuePair(key, value.Value, confidence));
        }