https://www.graalvm.org/ 
public class org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance extends com.oracle.truffle.api.instrumentation.TruffleInstrument implements org.graalvm.tools.api.lsp.LSPExtension
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance
  super_class: com.oracle.truffle.api.instrumentation.TruffleInstrument
{
  protected static final java.lang.String COMMAND_SIMPLE;
    descriptor: Ljava/lang/String;
    flags: (0x001c) ACC_PROTECTED, ACC_STATIC, ACC_FINAL
    ConstantValue: "lsp_test_extension_simple_command"

  protected static final java.lang.String COMMAND_TIMEOUT;
    descriptor: Ljava/lang/String;
    flags: (0x001c) ACC_PROTECTED, ACC_STATIC, ACC_FINAL
    ConstantValue: "lsp_test_extension_timeout_command"

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance this
         0: .line 38
            aload 0 /* this */
            invokespecial com.oracle.truffle.api.instrumentation.TruffleInstrument.<init>:()V
            return
        end local 0 // org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/graalvm/tools/lsp/test/server/LSPExtensionTestInstance;

  public java.util.List<org.graalvm.tools.api.lsp.LSPCommand> getCommands();
    descriptor: ()Ljava/util/List;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=5, locals=1, args_size=1
        start local 0 // org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance this
         0: .line 43
            iconst_2
            anewarray org.graalvm.tools.api.lsp.LSPCommand
            dup
            iconst_0
            new org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance$LSPExtensionTestSimpleCommand
            dup
            invokespecial org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance$LSPExtensionTestSimpleCommand.<init>:()V
            aastore
            dup
            iconst_1
            new org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance$LSPExtensionTestTimeoutCommand
            dup
            invokespecial org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance$LSPExtensionTestTimeoutCommand.<init>:()V
            aastore
            invokestatic java.util.Arrays.asList:([Ljava/lang/Object;)Ljava/util/List;
            areturn
        end local 0 // org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/graalvm/tools/lsp/test/server/LSPExtensionTestInstance;
    Signature: ()Ljava/util/List<Lorg/graalvm/tools/api/lsp/LSPCommand;>;

  protected void onCreate(com.oracle.truffle.api.instrumentation.TruffleInstrument$Env);
    descriptor: (Lcom/oracle/truffle/api/instrumentation/TruffleInstrument$Env;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance this
        start local 1 // com.oracle.truffle.api.instrumentation.TruffleInstrument$Env env
         0: .line 48
            aload 1 /* env */
            aload 0 /* this */
            invokevirtual com.oracle.truffle.api.instrumentation.TruffleInstrument$Env.registerService:(Ljava/lang/Object;)V
         1: .line 49
            return
        end local 1 // com.oracle.truffle.api.instrumentation.TruffleInstrument$Env env
        end local 0 // org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lorg/graalvm/tools/lsp/test/server/LSPExtensionTestInstance;
            0    2     1   env  Lcom/oracle/truffle/api/instrumentation/TruffleInstrument$Env;
    MethodParameters:
      Name  Flags
      env   
}
SourceFile: "LSPExtensionTestInstance.java"
NestMembers:
  org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance$LSPExtensionTestSimpleCommand  org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance$LSPExtensionTestTimeoutCommand
InnerClasses:
  public final Env = com.oracle.truffle.api.instrumentation.TruffleInstrument$Env of com.oracle.truffle.api.instrumentation.TruffleInstrument
  public abstract Registration = com.oracle.truffle.api.instrumentation.TruffleInstrument$Registration of com.oracle.truffle.api.instrumentation.TruffleInstrument
  private LSPExtensionTestSimpleCommand = org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance$LSPExtensionTestSimpleCommand of org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance
  private LSPExtensionTestTimeoutCommand = org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance$LSPExtensionTestTimeoutCommand of org.graalvm.tools.lsp.test.server.LSPExtensionTestInstance
    RuntimeVisibleAnnotations: 
      com.oracle.truffle.api.instrumentation.TruffleInstrument$Registration(id = "lsp-extension-test", name = "LSPExtension Test Instance", version = "0.1", services = {Lorg/graalvm/tools/api/lsp/LSPExtension;})