public String getJsonString() throws IOException {
    try (OutputStream outputStream = new ByteArrayOutputStream()) {
      new ObjectMapper().writeValue(outputStream, this);
      return outputStream.toString();
    }
  }
Return JSON representation of the SyncMap.

@return the json string representation of this SyncMap
@throws IOException if json serialization fails
jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/SkaffoldSyncMapTemplate.java