fn build_explicit(
values: &mut Vec<JsonVariant>,
explicit_type: &JsonNativeType,
preserve_empty_structs: bool,
project: impl FnMut(JsonVariant) -> Result<Option<BTreeMap<String, JsonVariant>>>,
) -> Result<VectorRef>fn build_explicit(
values: &mut Vec<JsonVariant>,
explicit_type: &JsonNativeType,
preserve_empty_structs: bool,
project: impl FnMut(JsonVariant) -> Result<Option<BTreeMap<String, JsonVariant>>>,
) -> Result<VectorRef>