c# - How to add a setter when there is a custom getter? -

i have modify existing code , stumped on getter setter. how add setter code?

public virtual string sku {     { return product.id.trim(); } }

depending on want in setter. if want assign value product.id should this:

public virtual string sku {     { return product.id.trim(); }     set { product.id = value; } }

in case set private field this:

private string _sku;  public virtual string sku {     { return product.id.trim(); }     set { _sku = value; } }

but bit akward have setter set field, whereas when getting value different.

the natural solution seem be:

private string _sku;  public virtual string sku {     { return _sku.trim(); }     set { _sku = value; } }

but not know exact rules of business logic.

Test