code: public UpdateContainerInstancesStateResult withContainerInstances(ContainerInstance... containerInstances) {
          if (this.containerInstances == null) {
              setContainerInstances(new com.amazonaws.internal.SdkInternalList<ContainerInstance>(containerInstances.length));
          }
          for (ContainerInstance ele : containerInstances) {
              this.containerInstances.add(ele);
          }
          return this;
      }
docs: <p>
  The list of container instances.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setContainerInstances(java.util.Collection)} or {@link #withContainerInstances(java.util.Collection)} if
  you want to override the existing values.
  </p>
  
  @param containerInstances
  The list of container instances.
  @return Returns a reference to this object so that method calls can be chained together.