public boolean removeFromList(String propertyName, String value) {
        final Lock writeLock = readWriteLock.writeLock();
        writeLock.lock();
        try {
            List<String> properties = getProperties(propertyName, true);
            boolean propertyWasRemoved = properties.remove(value);
            if (propertyWasRemoved) {
                setProperties(propertyName, properties);
            }
            return propertyWasRemoved;
        } finally {
            writeLock.unlock();
        }
    }
Removes the given value from the list of values represented by the property name.
The property is deleted if it no longer contains any values.

@param propertyName The name of the property list to change
@param value The value to be removed from the list
@return True if the value was removed from the list; false if the value was not found
xmppserver/src/main/java/org/jivesoftware/util/XMLProperties.java