Thinking in Java where did the BufferedInputFile class go?

Question

Java

The book Thinking in Java has this example:

//: io/MemoryInput.java 
import java.io.*;
public class MemoryInput { 
    public static void main(String[] args) throws IOException { 
    StringReader in = new StringReader( 
        BufferedInputFile.read("MemoryInput.java")); 
    int c; 
    while((c = in.read()) != -1) 
        System.out.print((char)c); 
    } 
} /* (Execute to see output) *///:~

Intellij doesn't know what BufferedInputFile is .
I'm using jdk 1.8.0
Where did this class go?

Answer 1

When I read this book, I also hung on this example. You flip the page back, there is an example with the creation of this class.