@JsonProperty(JSON_PROPERTY_INSTANCE)
  @JsonInclude(value = JsonInclude.Include.USE_DEFAULTS)
  public void setInstance(String instance) {
    this.instance = instance;
  }
A URI reference that identifies the specific occurrence of the problem. It may or may not yield further information if dereferenced. 
@return instance
plc4j/drivers/ctrlx/src/main/java/org/apache/plc4x/java/ctrlx/readwrite/rest/datalayer/model/Problem.java