Fix imports

Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>

Author: chemicL

mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransport.java

@@ -30,7 +30,18 @@
 import io.modelcontextprotocol.json.McpJsonDefaults;
 import io.modelcontextprotocol.json.McpJsonMapper;
 import io.modelcontextprotocol.json.TypeRef;
-import io.modelcontextprotocol.spec.*;
+import io.modelcontextprotocol.spec.ClosedMcpTransportSession;
+import io.modelcontextprotocol.spec.DefaultMcpTransportSession;
+import io.modelcontextprotocol.spec.DefaultMcpTransportStream;
+import io.modelcontextprotocol.spec.HttpHeaders;
+import io.modelcontextprotocol.spec.McpClientTransport;
+import io.modelcontextprotocol.spec.McpSchema;
+import io.modelcontextprotocol.spec.McpTransportException;
+import io.modelcontextprotocol.spec.McpTransportSession;
+import io.modelcontextprotocol.spec.McpTransportSessionClosedException;
+import io.modelcontextprotocol.spec.McpTransportSessionNotFoundException;
+import io.modelcontextprotocol.spec.McpTransportStream;
+import io.modelcontextprotocol.spec.ProtocolVersions;
 import io.modelcontextprotocol.util.Assert;
 import io.modelcontextprotocol.util.Utils;
 import org.reactivestreams.Publisher;