https://openjdk.java.net/ 
public interface sun.net.www.protocol.http.HttpAuthenticator
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: sun.net.www.protocol.http.HttpAuthenticator
  super_class: java.lang.Object
{
  public abstract boolean schemeSupported(java.lang.String);
    descriptor: (Ljava/lang/String;)Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
        Name  Flags
      scheme  

  public abstract java.lang.String authString(java.net.URL, java.lang.String, java.lang.String);
    descriptor: (Ljava/net/URL;Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
        Name  Flags
      u       
      scheme  
      realm   
}
SourceFile: "HttpAuthenticator.java"
    RuntimeVisibleAnnotations: 
      java.lang.Deprecated()