Return void from McpStatelessSyncServer#closeGracefully instead of Mono

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>

Author: tzolov

mcp-core/src/main/java/io/modelcontextprotocol/server/McpStatelessSyncServer.java

@@ -50,10 +50,10 @@ public McpSchema.Implementation getServerInfo() {
 
 	/**
 	 * Gracefully closes the server, allowing any in-progress operations to complete.
-	 * @return A Mono that completes when the server has been closed
+	 *
 	 */
-	public Mono<Void> closeGracefully() {
-		return this.asyncServer.closeGracefully();
+	public void closeGracefully() {
+		this.asyncServer.closeGracefully().block();
 	}
 
 	/**

mcp-test/src/main/java/io/modelcontextprotocol/AbstractStatelessIntegrationTests.java

@@ -4,8 +4,6 @@
 
 package io.modelcontextprotocol;
 
-import static io.modelcontextprotocol.util.ToolsUtils.EMPTY_JSON_SCHEMA;
-
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
@@ -31,9 +29,9 @@
 import net.javacrumbs.jsonunit.core.Option;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
-import org.junit.jupiter.params.provider.ValueSource;
 import reactor.core.publisher.Mono;
 
+import static io.modelcontextprotocol.util.ToolsUtils.EMPTY_JSON_SCHEMA;
 import static net.javacrumbs.jsonunit.assertj.JsonAssertions.assertThatJson;
 import static net.javacrumbs.jsonunit.assertj.JsonAssertions.json;
 import static org.assertj.core.api.Assertions.assertThat;
@@ -128,7 +126,7 @@ void testToolCallSuccess(String clientType) {
 			assertThat(response).isNotNull().isEqualTo(callResponse);
 		}
 		finally {
-			mcpServer.closeGracefully().block();
+			mcpServer.closeGracefully();
 		}
 	}