code: public java.util.List<ReceiptRuleSetMetadata> getRuleSets() {
          if (ruleSets == null) {
              ruleSets = new com.amazonaws.internal.SdkInternalList<ReceiptRuleSetMetadata>();
          }
          return ruleSets;
      }
docs: <p>
  The metadata for the currently active receipt rule set. The metadata consists of the rule set name and the
  timestamp of when the rule set was created.
  </p>
  
  @return The metadata for the currently active receipt rule set. The metadata consists of the rule set name and
  the timestamp of when the rule set was created.