interface VocabularyInterface

interface VocabularyInterface extends ConfigEntityInterface {
    
    /**
     * Denotes that no term in the vocabulary has a parent.
     */
    const HIERARCHY_DISABLED = 0;
    
    /**
     * Denotes that one or more terms in the vocabulary has a single parent.
     */
    const HIERARCHY_SINGLE = 1;
    
    /**
     * Denotes that one or more terms in the vocabulary have multiple parents.
     */
    const HIERARCHY_MULTIPLE = 2;
    
    /**
     * Returns the vocabulary hierarchy.
     *
     * @return int
     *   The vocabulary hierarchy.
     *
     * @deprecated in drupal:8.7.0 and is removed from drupal:9.0.0. Use
     *   \Drupal\taxonomy\TermStorage::getVocabularyHierarchyType() instead.
     */
    public function getHierarchy();
    
    /**
     * Sets the vocabulary hierarchy.
     *
     * @param int $hierarchy
     *   The hierarchy type of vocabulary.
     *   Possible values:
     *    - VocabularyInterface::HIERARCHY_DISABLED: No parents.
     *    - VocabularyInterface::HIERARCHY_SINGLE: Single parent.
     *    - VocabularyInterface::HIERARCHY_MULTIPLE: Multiple parents.
     *
     * @return $this
     *
     * @deprecated in drupal:8.7.0 and is removed from drupal:9.0.0. Reset
     *   the cache of the taxonomy_term storage handler instead.
     */
    public function setHierarchy($hierarchy);
    
    /**
     * Returns the vocabulary description.
     *
     * @return string
     *   The vocabulary description.
     */
    public function getDescription();

}