https://ant.apache.org/: master POM (The Apache Software Foundation) 
interface org.apache.tools.ant.taskdefs.Concat$ReaderFactory<S>
  minor version: 0
  major version: 59
  flags: flags: (0x0600) ACC_INTERFACE, ACC_ABSTRACT
  this_class: org.apache.tools.ant.taskdefs.Concat$ReaderFactory
  super_class: java.lang.Object
{
  public abstract java.io.Reader getReader(S);
    descriptor: (Ljava/lang/Object;)Ljava/io/Reader;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Exceptions:
      throws java.io.IOException
    Signature: (TS;)Ljava/io/Reader;
    MethodParameters:
      Name  Flags
      s     
}
Signature: <S:Ljava/lang/Object;>Ljava/lang/Object;
SourceFile: "Concat.java"
NestHost: org.apache.tools.ant.taskdefs.Concat
InnerClasses:
  private abstract ReaderFactory = org.apache.tools.ant.taskdefs.Concat$ReaderFactory of org.apache.tools.ant.taskdefs.Concat