https://logging.apache.org/log4j/2.x/log4j-core/: The Apache Log4j Implementation (The Apache Software Foundation)
  • Ralph Goers (Nextiva)
  • Gary Gregory (Rocket Software)
  • Scott Deboy
  • Remko Popma
  • Nick Williams
  • Matt Sicker (CloudBees)
  • Bruce Brouwer
  • Mikael Ståldal (Spotify)
  • Carter Kozak 
public final class org.apache.logging.log4j.core.util.SystemClock implements org.apache.logging.log4j.core.util.Clock
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: org.apache.logging.log4j.core.util.SystemClock
  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.logging.log4j.core.util.SystemClock this
         0: .line 22
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // org.apache.logging.log4j.core.util.SystemClock this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/apache/logging/log4j/core/util/SystemClock;

  public long currentTimeMillis();
    descriptor: ()J
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // org.apache.logging.log4j.core.util.SystemClock this
         0: .line 30
            invokestatic java.lang.System.currentTimeMillis:()J
            lreturn
        end local 0 // org.apache.logging.log4j.core.util.SystemClock this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/apache/logging/log4j/core/util/SystemClock;
}
SourceFile: "SystemClock.java"