src/vs/workbench/contrib/debug/common/debugModel.ts/ExpressionContainer/value
class ExpressionContainer:	set value(value: string) {
		this._value = value;
		this.valueChanged = !!ExpressionContainer.allValues.get(this.getId()) &&
			ExpressionContainer.allValues.get(this.getId()) !== Expression.DEFAULT_VALUE && ExpressionContainer.allValues.get(this.getId()) !== value;
		ExpressionContainer.allValues.set(this.getId(), value);
	}