src/vs/workbench/contrib/codeEditor/browser/languageConfigurationExtensionPoint.ts/LanguageConfigurationFileHandler/_extractValidColorizedBracketPairs
class LanguageConfigurationFileHandler:	private _extractValidColorizedBracketPairs(languageId: string, configuration: ILanguageConfiguration): CharacterPair[] | undefined {
		const source = configuration.colorizedBracketPairs;
		if (typeof source === 'undefined') {
			return undefined;
		}
		if (!Array.isArray(source)) {
			console.warn(`[${languageId}]: language configuration: expected \`colorizedBracketPairs\` to be an array.`);
			return undefined;
		}

		const result: CharacterPair[] = [];
		for (let i = 0, len = source.length; i < len; i++) {
			const pair = source[i];
			if (!isCharacterPair(pair)) {
				console.warn(`[${languageId}]: language configuration: expected \`colorizedBracketPairs[${i}]\` to be an array of two strings.`);
				continue;
			}
			result.push([pair[0], pair[1]]);

		}
		return result;
	}