Revert "Maybe expose this publicly?"

This reverts commit f00baa7.

include/openPMD/auxiliary/JSON.hpp

@@ -61,8 +61,5 @@ namespace json
      */
     std::string
     merge(std::string const &defaultValue, std::string const &overwrite);
-
-    std::string filterByTemplate(
-        std::string const &defaultValue, std::string const &positiveMask);
 } // namespace json
 } // namespace openPMD

src/auxiliary/JSON.cpp

@@ -632,26 +632,4 @@ filterByTemplate(nlohmann::json &defaultVal, nlohmann::json const &positiveMask)
     } // else noop
     return defaultVal;
 }
-
-std::string filterByTemplate(
-    std::string const &defaultValue, std::string const &positiveMask)
-{
-    auto [res, returnFormat] =
-        parseOptions(defaultValue, /* considerFiles = */ false);
-    filterByTemplate(
-        res, parseOptions(positiveMask, /* considerFiles = */ false).config);
-    switch (returnFormat)
-    {
-    case SupportedLanguages::JSON:
-        return res.dump();
-        break;
-    case SupportedLanguages::TOML: {
-        auto asToml = json::jsonToToml(res);
-        std::stringstream sstream;
-        sstream << asToml;
-        return sstream.str();
-    }
-    }
-    throw std::runtime_error("Unreachable!");
-}
 } // namespace openPMD::json

src/binding/python/Series.cpp

@@ -434,9 +434,4 @@ users to overwrite default options, while keeping any other ones.
                  If `defaultValue` was a JSON dataset, then as a JSON string,
                  otherwise as a TOML string.
         )END");
-    m.def(
-        "filter_json_by_template",
-        &json::filterByTemplate,
-        py::arg("default_value") = "{}",
-        py::arg("positive_mask") = "{}");
 }