assertThat(parse(url, "a\u0000b=cd")).isNull()
    assertThat(parse(url, "ab=c\u0000d")).isNull()
    assertThat(parse(url, "a\u0001b=cd")).isNull()
    assertThat(parse(url, "ab=c\u0001d")).isNull()
    assertThat(parse(url, "a\u0009b=cd")).isNull()
    assertThat(parse(url, "ab=c\u0009d")).isNull()
    assertThat(parse(url, "a\u001fb=cd")).isNull()
    assertThat(parse(url, "ab=c\u001fd")).isNull()

    assertThat(Ints.tryParse("")).isNull();
    assertThat(Ints.tryParse("-")).isNull();
    assertThat(Ints.tryParse("+1")).isNull();
    assertThat(Ints.tryParse("9999999999999999")).isNull();
    assertWithMessage("Max integer + 1")
        .that(Ints.tryParse(Long.toString(((long) GREATEST) + 1)))
        .isNull();
    assertWithMessage("Max integer * 10")

        .build()
    assertThat(request.tag()).isNull()
    assertThat(request.tag(Any::class.java)).isNull()
    assertThat(request.tag(UUID::class.java)).isNull()
    assertThat(request.tag(String::class.java)).isNull()

    // Alternate access APIs also work.
    assertThat(request.tag<String>()).isNull()
    assertThat(request.tag(String::class)).isNull()
  }

  @Test
  fun defaultTag() {

        String nullName = null;
        doThrow(new jcifs.CIFSException("invalid dfs name")).when(transport).getDfsReferrals(eq(ctx), isNull(), any(), any(), anyInt());

        assertThrows(jcifs.CIFSException.class, () -> transport.getDfsReferrals(ctx, nullName, "h", "d", 1));
        verify(transport).getDfsReferrals(eq(ctx), isNull(), eq("h"), eq("d"), eq(1));
    }

    // Signing modes: optional vs enforced
    @Test

      val source = response.body.source()
      assertThat(response.header("h1")).isEqualTo("v1")
      assertThat(response.peekTrailers()).isNull()
      assertFailsWith<IOException> {
        source.readUtf8()
      }
      try {
        assertThat(response.peekTrailers()).isNull() // Okay. This is what HTTP/1 does.
      } catch (_: IOException) {
        // Also okay. This is what HTTP/2 does.
      }

    assertThat("https://co.uk".toHttpUrl().topPrivateDomain()).isNull()
    assertThat("https://square".toHttpUrl().topPrivateDomain()).isNull()
    assertThat("https://栃木.jp".toHttpUrl().topPrivateDomain()).isNull()
    assertThat("https://xn--4pvxs.jp".toHttpUrl().topPrivateDomain()).isNull()
    assertThat("https://localhost".toHttpUrl().topPrivateDomain()).isNull()
    assertThat("https://127.0.0.1".toHttpUrl().topPrivateDomain()).isNull()

        SmbTreeImpl tree = mock(SmbTreeImpl.class);
        doReturn(tree).when(session).getSmbTree(eq("LOGON$"), isNull());

        // Act
        session.treeConnectLogon();

        // Assert: treeConnect invoked once with null params
        verify(tree, times(1)).treeConnect(isNull(), isNull());
        // Close of try-with-resources should call close on the mock
        verify(tree, times(1)).close();
    }

import assertk.assertions.containsExactly
import assertk.assertions.isEqualTo
import assertk.assertions.isInstanceOf
import assertk.assertions.isNotInstanceOf
import assertk.assertions.isNotNull
import assertk.assertions.isNull
import assertk.assertions.isSameAs
import java.io.IOException
import java.net.CookieManager
import java.net.Proxy
import java.net.ProxySelector
import java.net.ResponseCache
import java.net.SocketAddress

        boundary = "simple boundary",
        source = Buffer().writeUtf8(multipart),
      )

    assertThat(parts.nextPart()).isNotNull()
    assertThat(parts.nextPart()).isNull()
    assertThat(parts.nextPart()).isNull()
  }

  @Test fun `empty source`() {
    val parts =
      MultipartReader(
        boundary = "simple boundary",
        source = Buffer(),
      )

  }

  /*
   * Tests for Predicates.isNull()
   */

  public void testIsNull_apply() {
    Predicate<@Nullable Integer> isNull = Predicates.isNull();
    assertTrue(isNull.apply(null));
    assertFalse(isNull.apply(1));
  }

  public void testIsNull_equality() {
    new EqualsTester()
        .addEqualityGroup(Predicates.isNull(), Predicates.isNull())
        .addEqualityGroup(Predicates.notNull())