@ElementTypesAreNonnullByDefault
final class CollectPreconditions {

  static void checkEntryNotNull(Object key, Object value) {
    if (key == null) {
      throw new NullPointerException("null key in entry: null=" + value);
    } else if (value == null) {
      throw new NullPointerException("null value in entry: " + key + "=null");
    }
  }

  @CanIgnoreReturnValue
  static int checkNonnegative(int value, String name) {
    if (value < 0) {

@ElementTypesAreNonnullByDefault
final class CollectPreconditions {

  static void checkEntryNotNull(Object key, Object value) {
    if (key == null) {
      throw new NullPointerException("null key in entry: null=" + value);
    } else if (value == null) {
      throw new NullPointerException("null value in entry: " + key + "=null");
    }
  }

  @CanIgnoreReturnValue
  static int checkNonnegative(int value, String name) {
    if (value < 0) {

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

class FileSourceTest {

    @Test
    void testFileSource() {
        NullPointerException e = assertThrows(
                NullPointerException.class,
                () -> new FileSource((File) null),
                "Should fail, since you must specify a file");
        assertEquals("file cannot be null", e.getMessage());
    }

  }

  @MapFeature.Require(absent = ALLOWS_NULL_VALUE_QUERIES)
  public void testContainsNullValueFails() {
    try {
      multimap().containsValue(null);
      fail("Expected NullPointerException");
    } catch (NullPointerException expected) {
      // success
    }
  }

  public void testRemove_nullNotSupported() {
    try {
      assertFalse(
          "remove(null) should return false or throw NullPointerException",
          collection.remove(null));
    } catch (NullPointerException tolerated) {
    }
    expectUnchanged();
  }

  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_QUERIES})
  public void testRemove_nullAllowed() {

  public void testAddAll_nullCollectionReference() {
    try {
      collection.addAll(null);
      fail("addAll(null) should throw NullPointerException");
    } catch (NullPointerException expected) {
    }
  }

  /**
   * Returns the {@link Method} instance for {@link #testAddAll_nullUnsupported()} so that tests can
   * suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()} until <a

  }

  @MapFeature.Require(absent = ALLOWS_NULL_VALUE_QUERIES)
  public void testContainsNullValueFails() {
    try {
      multimap().containsValue(null);
      fail("Expected NullPointerException");
    } catch (NullPointerException expected) {
      // success
    }
  }

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

class UrlSourceTest {

    @Test
    void testUrlSource() {
        NullPointerException e = assertThrows(
                NullPointerException.class, () -> new UrlSource(null), "Should fail, since you must specify a url");
        assertEquals("url cannot be null", e.getMessage());
    }

    @Test

    assertSame(canonical, pool.intern(canonical));
    assertSame(canonical, pool.intern(not));
  }

  public void testStrong_null() {
    Interner<String> pool = Interners.newStrongInterner();
    assertThrows(NullPointerException.class, () -> pool.intern(null));
  }

  public void testStrong_builder() {
    int concurrencyLevel = 42;
    Interner<Object> interner =

  }

  @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
  public void testGetNullForbidden() {
    try {
      multimap().get(null);
      fail("Expected NullPointerException");
    } catch (NullPointerException expected) {
      // success
    }
  }

  @MapFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testGetWithNullValue() {