https://openjdk.java.net/ 
public interface java.nio.file.DirectoryStream$Filter<T>
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: java.nio.file.DirectoryStream$Filter
  super_class: java.lang.Object
{
  public abstract boolean accept();
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Exceptions:
      throws java.io.IOException
    Signature: (TT;)Z
    MethodParameters:
       Name  Flags
      entry  
}
Signature: <T:Ljava/lang/Object;>Ljava/lang/Object;
SourceFile: "DirectoryStream.java"
NestHost: java.nio.file.DirectoryStream
InnerClasses:
  public abstract Filter = java.nio.file.DirectoryStream$Filter of java.nio.file.DirectoryStream
    RuntimeVisibleAnnotations: 
      java.lang.FunctionalInterface()