--- a/src/goodjava/rpc/FixedLengthInputStream.java	Sat May 02 16:28:24 2020 -0600
+++ b/src/goodjava/rpc/FixedLengthInputStream.java	Sat May 02 20:42:28 2020 -0600
@@ -6,53 +6,10 @@
 import java.io.EOFException;
 
 
-public class FixedLengthInputStream extends FilterInputStream {
-	private long left;
+final class FixedLengthInputStream extends goodjava.io.FixedLengthInputStream {
 
 	public FixedLengthInputStream(InputStream in,long len) {
-		super(in);
-		if( len < 0 )
-			throw new IllegalArgumentException("len can't be negative");
-		this.left = len;
-	}
-
-	public int read() throws IOException {
-		if( left == 0 )
-			return -1;
-		int n = in.read();
-		if( n == -1 )
-			throw new EOFException();
-		left--;
-		return n;
-	}
-
-	public int read(byte b[], int off, int len) throws IOException {
-		if( len == 0 )
-			return 0;
-		if( left == 0 )
-			return -1;
-		if( len > left )
-			len = (int)left;
-		int n = in.read(b, off, len);
-		if( n == -1 )
-			throw new EOFException();
-		left -= n;
-		return n;
-	}
-
-	public long skip(long n) throws IOException {
-		if( n > left )
-			n = left;
-		n = in.skip(n);
-		left -= n;
-		return n;
-	}
-
-	public int available() throws IOException {
-		int n = in.available();
-		if( n > left )
-			n = (int)left;
-		return n;
+		super(in,len);
 	}
 
     public void close() throws IOException {
@@ -62,14 +19,4 @@
 		}
     }
 
-	public void mark(int readlimit) {}
-
-	public void reset() throws IOException {
-		throw new IOException("not supported");
-	}
-
-	public boolean markSupported() {
-		return false;
-	}
-
 }