public boolean containsKey(int key) {
    int hash = hash(key);
    return segmentFor(hash).containsKey(key, hash);
  }
Tests if the specified object is a key in this table.

@param key possible key
@return <tt>true</tt> if and only if the specified object is a key in this table, as determined
        by the <tt>equals</tt> method; <tt>false</tt> otherwise.
@throws NullPointerException if the specified key is null
geode-core/src/main/java/org/apache/geode/internal/ObjIdConcurrentMap.java