code: public void setTopicNames(java.util.Collection<String> topicNames) {
          if (topicNames == null) {
              this.topicNames = null;
              return;
          }
  
          this.topicNames = new com.amazonaws.internal.SdkInternalList<String>(topicNames);
      }
docs: <p>
  A list of SNS topic names for which to obtain the information. If this member is null, all associations for the
  specified Directory ID are returned.
  </p>
  <p>
  An empty list results in an <code>InvalidParameterException</code> being thrown.
  </p>
  
  @param topicNames
  A list of SNS topic names for which to obtain the information. If this member is null, all associations
  for the specified Directory ID are returned.</p>
  <p>
  An empty list results in an <code>InvalidParameterException</code> being thrown.