Bug 49714 [Dialogs] JRE wizard page is leaking an Image [build path]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/ClasspathContainerDescriptor.java
if (name == null) {
			throw new CoreException(new Status(IStatus.ERROR, JavaUI.ID_PLUGIN, 0, "Invalid extension (missing name): " + id, null)); 
		}
		if (pageClassName == null) {
			throw new CoreException(new Status(IStatus.ERROR, JavaUI.ID_PLUGIN, 0, "Invalid extension (missing page class name): " + id, null)); 
		}
	}
	public IClasspathContainerPage createPage() throws CoreException {
		Object elem= CoreUtility.createExtension(fConfigElement, ATT_PAGE_CLASS);
		if (elem instanceof IClasspathContainerPage) {
			return (IClasspathContainerPage) elem;
		} else {
			String id= fConfigElement.getAttribute(ATT_ID);
			throw new CoreException(new Status(IStatus.ERROR, JavaUI.ID_PLUGIN, 0, "Invalid extension (page not of type IClasspathContainerPage): " + id, null)); 
		}
	}
	public String getName() {
		return fConfigElement.getAttribute(ATT_NAME);
	}
	
	public String getPageClass() {
		return fConfigElement.getAttribute(ATT_PAGE_CLASS);
	}	
	public boolean canEdit(IClasspathEntry entry) {
		String id = fConfigElement.getAttribute(ATT_ID);
		if (entry.getEntryKind() == IClasspathEntry.CPE_CONTAINER) {
			String type = entry.getPath().segment(0);
			return id.equals(type);
		}
		return false;