https://github.com/oracle/graal: GraalVM is an ecosystem for compiling and running applications written in multiple languages. GraalVM removes the isolation between programming languages and enables interoperability in a shared runtime. 
class org.graalvm.options.OptionType$9 implements org.graalvm.options.OptionType$Converter<T>
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: org.graalvm.options.OptionType$9
  super_class: java.lang.Object
{
  private final java.util.function.Function val$stringConverter;
    descriptor: Ljava/util/function/Function;
    flags: (0x1012) ACC_PRIVATE, ACC_FINAL, ACC_SYNTHETIC

  void <init>(java.util.function.Function);
    descriptor: (Ljava/util/function/Function;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.graalvm.options.OptionType$9 this
         0: .line 79
            aload 0 /* this */
            aload 1
            putfield org.graalvm.options.OptionType$9.val$stringConverter:Ljava/util/function/Function;
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // org.graalvm.options.OptionType$9 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/graalvm/options/OptionType$9;
    MethodParameters:
                     Name  Flags
      val$stringConverter  final

  public T convert(T, java.lang.String, java.lang.String);
    descriptor: (Ljava/lang/Object;Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=4, args_size=4
        start local 0 // org.graalvm.options.OptionType$9 this
        start local 1 // java.lang.Object previousValue
        start local 2 // java.lang.String key
        start local 3 // java.lang.String value
         0: .line 82
            aload 0 /* this */
            getfield org.graalvm.options.OptionType$9.val$stringConverter:Ljava/util/function/Function;
            aload 3 /* value */
            invokeinterface java.util.function.Function.apply:(Ljava/lang/Object;)Ljava/lang/Object;
            areturn
        end local 3 // java.lang.String value
        end local 2 // java.lang.String key
        end local 1 // java.lang.Object previousValue
        end local 0 // org.graalvm.options.OptionType$9 this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    1     0           this  Lorg/graalvm/options/OptionType$9;
            0    1     1  previousValue  TT;
            0    1     2            key  Ljava/lang/String;
            0    1     3          value  Ljava/lang/String;
    Signature: (TT;Ljava/lang/String;Ljava/lang/String;)TT;
    MethodParameters:
               Name  Flags
      previousValue  
      key            
      value          
}
Signature: Ljava/lang/Object;Lorg/graalvm/options/OptionType$Converter<TT;>;
SourceFile: "OptionType.java"
EnclosingMethod: org.graalvm.options.OptionType.<init>:(Ljava/lang/String;Ljava/util/function/Function;Ljava/util/function/Consumer;)V
NestHost: org.graalvm.options.OptionType
InnerClasses:
  org.graalvm.options.OptionType$9
  private abstract Converter = org.graalvm.options.OptionType$Converter of org.graalvm.options.OptionType