code: public DescribeRetentionConfigurationsResult withRetentionConfigurations(RetentionConfiguration... retentionConfigurations) {
          if (this.retentionConfigurations == null) {
              setRetentionConfigurations(new com.amazonaws.internal.SdkInternalList<RetentionConfiguration>(retentionConfigurations.length));
          }
          for (RetentionConfiguration ele : retentionConfigurations) {
              this.retentionConfigurations.add(ele);
          }
          return this;
      }
docs: <p>
  Returns a retention configuration object.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setRetentionConfigurations(java.util.Collection)} or
  {@link #withRetentionConfigurations(java.util.Collection)} if you want to override the existing values.
  </p>
  
  @param retentionConfigurations
  Returns a retention configuration object.
  @return Returns a reference to this object so that method calls can be chained together.