public static bool operator ==(Livro lhs, Livro rhs)
{
// Check for null on left side.
if (Object.ReferenceEquals(lhs, null))
{
if (Object.ReferenceEquals(rhs, null))
{
// null == null = true.
return true;
}
// Only the left side is null.
return false;
}
// Equals handles case of null on right side.
return lhs.Equals(rhs);
}