@param key the key to check
file : https_github_com_apache_commons-collections_git/src/main/java/org/apache/commons/collections4/trie/KeyAnalyzer.java
file : https_github_com_apache_commons-collections_git/src/main/java/org/apache/commons/collections4/map/StaticBucketMap.java
file : https_github_com_apache_commons-collections_git/src/main/java/org/apache/commons/collections4/map/MultiKeyMap.java