@JsonInclude(JsonInclude.Include.NON_NULL)
  @JsonProperty("overrides")
  public Map<Long, String> getConfigGroupOverrides() {
    return configGroupOverrides;
  }
Data structure that hangs off of the Host and points to what tags are
applicable to a config derived at the host-level
ambari-server/src/main/java/org/apache/ambari/server/state/HostConfig.java