import org.junit.jupiter.params.provider.ValueSource;

/**
 * Test class for StringUtil utility methods
 */
class StringUtilTest {

    @Test
    @DisplayName("Should join single element without delimiter")
    void testJoinSingleElement() {
        String result = StringUtil.join(",", "hello");
        assertEquals("hello", result);
    }

    @Test

  /** Test an empty collection. */
  ZERO(0),
  /** Test a one-element collection. */
  ONE(1),
  /** Test a three-element collection. */
  SEVERAL(3),
  /*
   * TODO: add VERY_LARGE, noting that we currently assume that the fourth
   * sample element is not in any collection
   */

  ANY(ZERO, ONE, SEVERAL);

  private final Set<Feature<? super Collection>> implied;

  // Load factor and capacity for "inner" (i.e. per node/edge element) hash sets or maps
  static final float INNER_LOAD_FACTOR = 1.0f;
  static final int INNER_CAPACITY = 2; // ceiling(EXPECTED_DEGREE / INNER_LOAD_FACTOR)

  // Error messages
  static final String NODE_NOT_IN_GRAPH = "Node %s is not an element of this graph.";
  static final String EDGE_NOT_IN_GRAPH = "Edge %s is not an element of this graph.";
  static final String NODE_REMOVED_FROM_GRAPH =

  /** Test an empty collection. */
  ZERO(0),
  /** Test a one-element collection. */
  ONE(1),
  /** Test a three-element collection. */
  SEVERAL(3),
  /*
   * TODO: add VERY_LARGE, noting that we currently assume that the fourth
   * sample element is not in any collection
   */

  ANY(ZERO, ONE, SEVERAL);

  private final Set<Feature<? super Collection>> implied;

        // Verify that the stack trace contains this test method
        boolean foundTestMethod = false;
        for (StackTraceElement element : exception.getStackTrace()) {
            if (element.getMethodName().equals("test_stackTrace") && element.getClassName().equals(this.getClass().getName())) {
                foundTestMethod = true;
                break;
            }
        }

	VDUP	V8.B[17], V3.B8                                  // ERROR "register element index out of range 0 to 15"
	VDUP	V8.H[9], V3.H4                                   // ERROR "register element index out of range 0 to 7"
	VDUP	V8.H[9], V3.H8                                   // ERROR "register element index out of range 0 to 7"

            writer.accept("Thread: " + entry.getKey());
            final StackTraceElement[] trace = entry.getValue();
            for (final StackTraceElement element : trace) {
                writer.accept("\tat " + element);
            }
        }
    }

              @Override
              public Collection<String> create(String[] elements) {
                // TODO: MinimalCollection should perhaps throw
                for (Object element : elements) {
                  if (element == null) {
                    throw new NullPointerException();
                  }
                }
                return MinimalCollection.of(elements);
              }
            })

   */
  ALLOWS_NULL_QUERIES,
  ALLOWS_NULL_VALUES(ALLOWS_NULL_QUERIES),

  /**
   * Indicates that a collection disallows certain elements (other than {@code null}, whose validity
   * as an element is indicated by the presence or absence of {@link #ALLOWS_NULL_VALUES}). From the
   * documentation for {@link Collection}:
   *
   * <blockquote>
   *

   * support concurrent multisets whose content may change while the method is running.
   *
   * <p>The serialized output consists of the number of distinct elements, the first element, its
   * count, the second element, its count, and so on.
   */
  static <E extends @Nullable Object> void writeMultiset(
      Multiset<E> multiset, ObjectOutputStream stream) throws IOException {