function isRestrictedPattern(importSource, group) {
			return group.regexMatcher
				? group.regexMatcher.test(importSource)
				: group.matcher.ignores(importSource);
		}
Check if the given importSource is restricted by a pattern.
@param {string} importSource path of the import
@param {Object} group contains a Ignore instance for paths, and the customMessage to show if it fails
@returns {boolean} whether the variable is a restricted pattern or not
@private