src/vs/editor/common/core/characterClassifier.ts/CharacterClassifier/constructor
class CharacterClassifier:	constructor(_defaultValue: T) {
		const defaultValue = toUint8(_defaultValue);

		this._defaultValue = defaultValue;
		this._asciiMap = CharacterClassifier._createAsciiMap(defaultValue);
		this._map = new Map<number, number>();
	}