Bug 190061 [Metadata] Update @since tags for new API
Patch to follow
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/Command.java
throw new NullPointerException(
					"Cannot remove a null command listener"); 
		}
		removeListenerObject(commandListener);
	}
	/**
	 * Removes a listener from this command.
	 * 
	 * @param executionListener
	 *            The listener to be removed; must not be <code>null</code>.
	 * 
	 */
	public final void removeExecutionListener(
			final IExecutionListener executionListener) {
		if (executionListener == null) {
			throw new NullPointerException(
					"Cannot remove a null execution listener"); 
		}
		if (executionListeners != null) {
			executionListeners.remove(executionListener);
			if (executionListeners.isEmpty()) {
				executionListeners = null;
			}
		}
	}
	/**
	 * <p>
	 * Removes a state from this command. This will remove the state from the
	 * active handler, if the active handler is an instance of
	 * {@link IObjectWithState}.