code: public void setHierarchyLevels(com.google.api.ads.admanager.axis.v201808.ContentMetadataKeyHierarchyLevel[] hierarchyLevels) {
          this.hierarchyLevels = hierarchyLevels;
      }
docs: Sets the hierarchyLevels value for this ContentMetadataKeyHierarchy.
  
  @param hierarchyLevels   * The levels of the {@code ContentMetadataKeyHierarchy}. This
  attribute is readonly and
  the hierarchy levels must form a continuous set of
  1, 2, ..., N where N is the number
  of levels in the hierarchy.