code: protected CatalogResolver createCatalogResolver() throws MojoExecutionException {
  		final CatalogManager catalogManager = new CatalogManager();
  		catalogManager.setIgnoreMissingProperties(true);
  		catalogManager.setUseStaticCatalog(false);
  		// TODO Logging
  		if (getLog().isDebugEnabled()) {
  			catalogManager.setVerbosity(Integer.MAX_VALUE);
  		}
  		if (getCatalogResolver() == null) {
  			return new MavenCatalogResolver(catalogManager, this, getLog());
  		} else {
  			final String catalogResolverClassName = getCatalogResolver().trim();
  			return createCatalogResolverByClassName(catalogResolverClassName);
  		}
  	}
docs: Creates an instance of catalog resolver.
  
  @return Instance of the catalog resolver.
  @throws MojoExecutionException
  If catalog resolver cannot be instantiated.