如何为单元测试流程中调用的静态方法返回不同的值？

public class StringUtils {
    public static boolean isBlank(String str) {
        return str == null || str.trim().isEmpty();
    }
}

<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-core</artifactId>
    <version>3.11.2</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.powermock</groupId>
    <artifactId>powermock-module-junit4</artifactId>
    <version>2.0.9</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.powermock</groupId>
    <artifactId>powermock-api-mockito2</artifactId>
    <version>2.0.9</version>
    <scope>test</scope>
</dependency>

import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

@RunWith(PowerMockRunner.class)
@PrepareForTest(StringUtils.class)
public class StringUtilsTest {

    @Test
    public void testIsBlank_ReturnsTrue() {
        PowerMockito.mockStatic(StringUtils.class);
        PowerMockito.when(StringUtils.isBlank("")).thenReturn(true);

        boolean result = StringUtils.isBlank("");
        assert result == true;
    }

    @Test
    public void testIsBlank_ReturnsFalse() {
        PowerMockito.mockStatic(StringUtils.class);
        PowerMockito.when(StringUtils.isBlank("Hello")).thenReturn(false);

        boolean result = StringUtils.isBlank("Hello");
        assert result == false;
    }
}

public interface StringChecker {
    boolean isBlank(String str);
}

public class DefaultStringChecker implements StringChecker {
    @Override
    public boolean isBlank(String str) {
        return StringUtils.isBlank(str);
    }
}

public class SomeService {
    private final StringChecker stringChecker;

    public SomeService(StringChecker stringChecker) {
        this.stringChecker = stringChecker;
    }

    public boolean checkString(String str) {
        return stringChecker.isBlank(str);
    }
}

import org.junit.Test;
import static org.mockito.Mockito.*;

public class SomeServiceTest {

    @Test
    public void testCheckString_ReturnsTrue() {
        StringChecker mockChecker = mock(StringChecker.class);
        when(mockChecker.isBlank("")).thenReturn(true);

        SomeService service = new SomeService(mockChecker);
        boolean result = service.checkString("");
        assert result == true;
    }

    @Test
 public void testCheckString_ReturnsFalse() {
        StringChecker mockChecker = mock(StringChecker.class);
        when(mockChecker.isBlank("Hello")).thenReturn(false);

        SomeService service = new SomeService(mockChecker);
        boolean result = service.checkString("Hello");
        assert result == false;
    }
}