private static Alias fromCatalog(String catalogName, String aliasName) {
		Catalog catalog = Catalog.getByName(catalogName);
		Alias alias = catalog.aliases.get(aliasName);
		if (alias == null) {
			throw new ExitException(EXIT_INVALID_INPUT, "No alias found with name '" + aliasName + "'");
		}
		return alias;
	}
Returns the given Alias from the given registered Catalog

@param catalogName The name of a registered Catalog
@param aliasName   The name of an Alias
@return An Alias object
src/main/java/dev/jbang/catalog/Alias.java