code: public ListConfigurationSetsResult withConfigurationSets(ConfigurationSet... configurationSets) {
          if (this.configurationSets == null) {
              setConfigurationSets(new com.amazonaws.internal.SdkInternalList<ConfigurationSet>(configurationSets.length));
          }
          for (ConfigurationSet ele : configurationSets) {
              this.configurationSets.add(ele);
          }
          return this;
      }
docs: <p>
  A list of configuration sets.
  </p>
  <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
  A list of configuration sets.
  @return Returns a reference to this object so that method calls can be chained together.