https://source.android.com/ 
public class android.os.NetworkOnMainThreadException extends java.lang.RuntimeException
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: android.os.NetworkOnMainThreadException
  super_class: java.lang.RuntimeException
{
  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // android.os.NetworkOnMainThreadException this
         0: .line 31
            aload 0 /* this */
            invokespecial java.lang.RuntimeException.<init>:()V
            return
        end local 0 // android.os.NetworkOnMainThreadException this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Landroid/os/NetworkOnMainThreadException;
}
SourceFile: "NetworkOnMainThreadException.java"