How is the principle of interface segregation implemented in real projects?

The Interface Segregation Principle in real projects is implemented by creating several specialized interfaces instead of a single general one. This allows clients to depend only on the methods that they actually need.

For example, instead of one large interface:

interface Printer {
    void print(Document d);
    void scan(Document d);
    void fax(Document d);
}

it's better to split into several:

interface IPrinter {
    void print(Document d);
}

interface IScanner {
    void scan(Document d);
}

interface IFax {
    void fax(Document d);
}

Classes can implement only the necessary interfaces, which simplifies support and extension of the code.