import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.*;

class TestCount7 {

    StringOperator strOp = new StringOperator();

    @Test
    void count7() {
        assertEquals(4, strOp.count7("7adaf7af7afafadf7"));
        assertEquals(0, strOp.count7(""));
        assertEquals(0, strOp.count7("khdagfha gahrgn 84q584q8"));
        assertEquals(5, strOp.count7("77777"));
        assertEquals(2, strOp.count7("7fa.fafa fadf7 a fa"));
        assertEquals(2, strOp.count7("cja fadf7 dafad fahd7"));
    }
}