code: public ReshardingConfiguration withPreferredAvailabilityZones(String... preferredAvailabilityZones) {
          if (this.preferredAvailabilityZones == null) {
              setPreferredAvailabilityZones(new com.amazonaws.internal.SdkInternalList<String>(preferredAvailabilityZones.length));
          }
          for (String ele : preferredAvailabilityZones) {
              this.preferredAvailabilityZones.add(ele);
          }
          return this;
      }
docs: <p>
  A list of preferred availability zones for the nodes in this cluster.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setPreferredAvailabilityZones(java.util.Collection)} or
  {@link #withPreferredAvailabilityZones(java.util.Collection)} if you want to override the existing values.
  </p>
  
  @param preferredAvailabilityZones
  A list of preferred availability zones for the nodes in this cluster.
  @return Returns a reference to this object so that method calls can be chained together.