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

class TestCount67 {

    private StringOperator strOp = new StringOperator();

    @Test
    void count67() {
        assertEquals(4, strOp.specialCount67("6Hi6a, hi7 hi:67 6a7"));
        assertEquals(1, strOp.specialCount67("6"));
        assertEquals(1, strOp.specialCount67("6a7a6"));
        assertEquals(6, strOp.specialCount67("676:676a6"));
        assertEquals(4, strOp.specialCount67("6-6-6a-6b-7a-67b-7"));
        assertEquals(5, strOp.specialCount67("67676"));
        assertEquals(0, strOp.specialCount67(""));
        assertEquals(0, strOp.specialCount67("12345"));
    }

}