https://freemarker.apache.org/: FreeMarker is a "template engine"; a generic tool to generate text output based on templates. (Apache Software Foundation) 
class freemarker.template.utility.ClassUtil$MaybeZipFileClosedException extends java.lang.Exception
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: freemarker.template.utility.ClassUtil$MaybeZipFileClosedException
  super_class: java.lang.Exception
{
  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // freemarker.template.utility.ClassUtil$MaybeZipFileClosedException this
         0: .line 500
            aload 0 /* this */
            invokespecial java.lang.Exception.<init>:()V
            return
        end local 0 // freemarker.template.utility.ClassUtil$MaybeZipFileClosedException this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lfreemarker/template/utility/ClassUtil$MaybeZipFileClosedException;
}
SourceFile: "ClassUtil.java"
NestHost: freemarker.template.utility.ClassUtil
InnerClasses:
  private MaybeZipFileClosedException = freemarker.template.utility.ClassUtil$MaybeZipFileClosedException of freemarker.template.utility.ClassUtil