https://openjdk.java.net/ 
public final class sun.security.rsa.RSAKeyPairGenerator$Legacy extends sun.security.rsa.RSAKeyPairGenerator
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: sun.security.rsa.RSAKeyPairGenerator$Legacy
  super_class: sun.security.rsa.RSAKeyPairGenerator
{
  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // sun.security.rsa.RSAKeyPairGenerator$Legacy this
         0: .line 190
            aload 0 /* this */
            getstatic sun.security.rsa.RSAUtil$KeyType.RSA:Lsun/security/rsa/RSAUtil$KeyType;
            getstatic sun.security.util.SecurityProviderConstants.DEF_RSA_KEY_SIZE:I
            invokespecial sun.security.rsa.RSAKeyPairGenerator.<init>:(Lsun/security/rsa/RSAUtil$KeyType;I)V
         1: .line 191
            return
        end local 0 // sun.security.rsa.RSAKeyPairGenerator$Legacy this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lsun/security/rsa/RSAKeyPairGenerator$Legacy;
}
SourceFile: "RSAKeyPairGenerator.java"
NestHost: sun.security.rsa.RSAKeyPairGenerator
InnerClasses:
  public final Legacy = sun.security.rsa.RSAKeyPairGenerator$Legacy of sun.security.rsa.RSAKeyPairGenerator
  public final KeyType = sun.security.rsa.RSAUtil$KeyType of sun.security.rsa.RSAUtil