public static String writeValueAsString(Object o) {
    try {
      return o == null ? null : MAPPERS.get().writeValueAsString(o);
    } catch (JsonProcessingException e) {
      throw new UncheckedIOException(e);
    }
  }
Utilities for converting between JSON strings and java objects using Jackson utilities.
<p>
{@link ObjectMapper} are expensive to construct, but not thread safe, so this class reuses the same object mapper
within each thread but does not share between threads.
planetiler-core/src/main/java/com/onthegomap/planetiler/reader/JsonConversion.java