Скачать или смотреть C# code duplicate solved using abstract class.

An abstract class is a class that is declared
abstract —it may or may not include.

abstract methods.
Abstract classes cannot be instantiated, but
they can be subclassed.

When an abstract class is subclassed, the
subclass usually provides implementations
for all of the abstract methods in its parent
class.

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Today
Let's duplicate code and then we
later clean it up using abstract class.

Remember

Duplicate code is generally considered
undesirable for a number of reasons.

Is more difficult to support, simply because
it is longer, and. because if it needs
updating, there is a danger that one copy of
the code will be updated without further
checking for the presence of other instances
of the same code.