code: @Override
  	public Object remove(final Object key) {
  		lock.writeLock().lock();
  		try {
  			final boolean useLocalPrefixes = !mixDefaultAndLocalPrefixes && hasLocalPrefixConfigurations();
  			final Object someKey = getPrefixedKey(key, useLocalPrefixes);
  			Object result = properties.remove(someKey);
  			if (result == null) {
  				result = properties.remove(key);
  			}
  			return result;
  		} finally {
  			lock.writeLock().unlock();
  		}
  	}
docs: /*
  (non-Javadoc)
  
  @see java.util.Hashtable#remove(java.lang.Object)