src/vs/platform/contextkey/common/contextkey.ts/ContextKeyOrExpr/equals
class ContextKeyOrExpr:	public equals(other: ContextKeyExpression): boolean {
		if (other.type === this.type) {
			if (this.expr.length !== other.expr.length) {
				return false;
			}
			for (let i = 0, len = this.expr.length; i < len; i++) {
				if (!this.expr[i].equals(other.expr[i])) {
					return false;
				}
			}
			return true;
		}
		return false;
	}