code: public DescribeDirectoryConfigsRequest withDirectoryNames(String... directoryNames) {
          if (this.directoryNames == null) {
              setDirectoryNames(new java.util.ArrayList<String>(directoryNames.length));
          }
          for (String ele : directoryNames) {
              this.directoryNames.add(ele);
          }
          return this;
      }
docs: <p>
  The directory names.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setDirectoryNames(java.util.Collection)} or {@link #withDirectoryNames(java.util.Collection)} if you want
  to override the existing values.
  </p>
  
  @param directoryNames
  The directory names.
  @return Returns a reference to this object so that method calls can be chained together.