https://www.graalvm.org/ 
class org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain$2 extends org.graalvm.component.installer.SimpleGetopt
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain$2
  super_class: org.graalvm.component.installer.SimpleGetopt
{
  final org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain this$1;
    descriptor: Lorg/graalvm/component/installer/InstallerCommandlineTest$MockInstallerMain;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  void <init>(org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain, java.util.Map);
    descriptor: (Lorg/graalvm/component/installer/InstallerCommandlineTest$MockInstallerMain;Ljava/util/Map;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain$2 this
        start local 2 // java.util.Map $anonymous0
         0: .line 99
            aload 0 /* this */
            aload 1
            putfield org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain$2.this$1:Lorg/graalvm/component/installer/InstallerCommandlineTest$MockInstallerMain;
            aload 0 /* this */
            aload 2 /* $anonymous0 */
            invokespecial org.graalvm.component.installer.SimpleGetopt.<init>:(Ljava/util/Map;)V
            return
        end local 2 // java.util.Map $anonymous0
        end local 0 // org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain$2 this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    1     0         this  Lorg/graalvm/component/installer/InstallerCommandlineTest$MockInstallerMain$2;
            0    1     2  $anonymous0  Ljava/util/Map<Ljava/lang/String;Ljava/lang/String;>;
    MethodParameters:
             Name  Flags
      this$0       final
      $anonymous0  

  public java.lang.RuntimeException err(java.lang.String, java.lang.Object[]);
    descriptor: (Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/RuntimeException;
    flags: (0x0081) ACC_PUBLIC, ACC_VARARGS
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain$2 this
        start local 1 // java.lang.String messageKey
        start local 2 // java.lang.Object[] aa
         0: .line 102
            aload 0 /* this */
            getfield org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain$2.this$1:Lorg/graalvm/component/installer/InstallerCommandlineTest$MockInstallerMain;
            aload 1 /* messageKey */
            aload 2 /* aa */
            invokevirtual org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain.error:(Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/RuntimeException;
            areturn
        end local 2 // java.lang.Object[] aa
        end local 1 // java.lang.String messageKey
        end local 0 // org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain$2 this
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    1     0        this  Lorg/graalvm/component/installer/InstallerCommandlineTest$MockInstallerMain$2;
            0    1     1  messageKey  Ljava/lang/String;
            0    1     2          aa  [Ljava/lang/Object;
    MethodParameters:
            Name  Flags
      messageKey  
      aa          
}
SourceFile: "InstallerCommandlineTest.java"
EnclosingMethod: org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain.createOptionsObject:(Ljava/util/Map;)Lorg/graalvm/component/installer/SimpleGetopt;
NestHost: org.graalvm.component.installer.InstallerCommandlineTest
InnerClasses:
  MockInstallerMain = org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain of org.graalvm.component.installer.InstallerCommandlineTest
  org.graalvm.component.installer.InstallerCommandlineTest$MockInstallerMain$2