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