code: public ListConfigurationSetsResult withConfigurationSets(String... configurationSets) {
          if (this.configurationSets == null) {
              setConfigurationSets(new java.util.ArrayList<String>(configurationSets.length));
          }
          for (String ele : configurationSets) {
              this.configurationSets.add(ele);
          }
          return this;
      }
docs: An object that contains a list of configuration sets for your account in the current region.
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setConfigurationSets(java.util.Collection)} or {@link #withConfigurationSets(java.util.Collection)} if
  you want to override the existing values.
  </p>
  
  @param configurationSets
  An object that contains a list of configuration sets for your account in the current region.
  @return Returns a reference to this object so that method calls can be chained together.