https://tomcat.apache.org/: Interface code to the native connector 
public class org.apache.tomcat.jni.Thread
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.apache.tomcat.jni.Thread
  super_class: java.lang.Object
{
  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.apache.tomcat.jni.Thread this
         0: .line 24
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // org.apache.tomcat.jni.Thread this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/apache/tomcat/jni/Thread;

  public static native long current();
    descriptor: ()J
    flags: (0x0109) ACC_PUBLIC, ACC_STATIC, ACC_NATIVE
}
SourceFile: "Thread.java"