public boolean contains(Object value) {
        return containsValue(value);
    }
Legacy method testing if some key maps into the specified value
in this table.  This method is identical in functionality to
{@link #containsValue}, and exists solely to ensure
full compatibility with class {@link java.util.Hashtable},
which supported this method prior to introduction of the
Java Collections framework.
@param  value a value to search for
@return <tt>true</tt> if and only if some key maps to the
        <tt>value</tt> argument in this table as
        determined by the <tt>equals</tt> method;
        <tt>false</tt> otherwise
@throws NullPointerException if the specified value is null
commons-profiler/src/main/java/com/navercorp/pinpoint/common/profiler/concurrent/jsr166/ConcurrentWeakHashMap.java