}

    /**
     * Subclasses implement the actual upgrade logic here.
     *
     * @param context the upgrade context
     * @param pomMap map of all POM files in the project
     * @return the result of the upgrade operation
     */
    protected abstract UpgradeResult doApply(UpgradeContext context, Map<Path, Document> pomMap);

    /**
     * Gets the upgrade options from the context.
     *

 * under the License.
 */

/**
 * Provides the API for the Maven Upgrade tool ({@code mvnup}).
 *
 * <p>This package contains interfaces and classes for the Maven upgrade tool,
 * which provides functionality for upgrading Maven projects and dependencies.</p>
 *
 * <p>Key features include:</p>
 * <ul>
 *   <li>Project upgrade capabilities</li>
 *   <li>Dependency version management</li>

      ProtocolException::class.java,
      "Expected 'Upgrade' header value 'websocket' but was 'null'",
    )
    webSocket.cancel()
  }

  @Test
  @Throws(IOException::class)
  fun wrongUpgradeHeader() {
    webServer.enqueue(
      MockResponse
        .Builder()
        .code(101)
        .setHeader("Connection", "Upgrade")
        .setHeader("Upgrade", "Pepsi")

 * specific language governing permissions and limitations
 * under the License.
 */

/**
 * Implementation of the Maven Upgrade tool ({@code mvnup}).
 *
 * <p>This package contains the implementation classes for the Maven upgrade tool,
 * providing functionality for upgrading Maven projects and dependencies.</p>
 *
 * @since 4.0.0
 */

    private const val UPGRADE = "upgrade"

    /** See http://tools.ietf.org/html/draft-ietf-httpbis-http2-09#section-8.1.3. */
    private val HTTP_2_SKIPPED_REQUEST_HEADERS =
      immutableListOf(
        CONNECTION,
        HOST,
        KEEP_ALIVE,
        PROXY_CONNECTION,
        TE,
        TRANSFER_ENCODING,
        ENCODING,
        UPGRADE,
        TARGET_METHOD_UTF8,

        }
    }

    @Nested
    @DisplayName("Upgrade Path Validation")
    class UpgradePathValidationTests {

        @ParameterizedTest(name = "from {0} to {1}")
        @MethodSource("provideValidPathUpgradeVersions")
        @DisplayName("should validate upgrade path")
        void shouldValidateUpgradePath(String from, String to) {

  }

  @Test fun http2HeadersListDropsForbiddenHeadersHttp2() {
    val request =
      Request
        .Builder()
        .url("http://square.com/")
        .header("Connection", "upgrade")
        .header("Upgrade", "websocket")
        .header("Host", "square.com")
        .header("TE", "gzip")
        .build()
    val expected =
      headerEntries(
        ":method",
        "GET",
        ":path",

    assertThat(recorded.headers["Connection"]).isEqualTo("Upgrade, HTTP2-Settings")
    if (PlatformVersion.majorVersion < 19) {
      assertThat(recorded.headers["Content-Length"]).isEqualTo("0")
    }
    assertThat(recorded.headers["HTTP2-Settings"]).isNotNull()
    assertThat(recorded.headers["Upgrade"]).isEqualTo("h2c") // HTTP/2 over plaintext!

    - [Node Binaries](#node-binaries)
    - [Container Images](#container-images)
  - [Changelog since v1.34.0](#changelog-since-v1340)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)
  - [Changes by Kind](#changes-by-kind)
    - [Deprecation](#deprecation)
    - [API Change](#api-change)
    - [Feature](#feature)

    permissions:
      pull-requests: read
    runs-on: ubuntu-latest
    steps:
      - uses: docker://agilepathway/pull-request-label-checker:latest
        with:
          one_of: breaking,security,feature,bug,refactor,upgrade,docs,lang-all,internal