import java.io.File;
import java.io.FileReader;
import java.io.FilterReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;

/**
 * Deeply opinionated file filter that adds elements to the release notes HTML page.
 */
public class ReleaseNotesTransformer extends FilterReader {
    private File baseCss;

erpolation; public abstract interface ValueSource { public abstract Object getValue(String); } org/codehaus/plexus/util/InterpolationFilterR.class package org.codehaus.plexus.util; public synchronized class InterpolationFilterR extends java.io.FilterReader { private String replaceData; private int replaceIndex; private java.util.Map variables; private String beginToken; private String endToken; private int beginTokenLength; private int endTokenLength; private static String DEFAULT_BEGIN_TOKEN; private...

include::sample[dir="snippets/files/copy/groovy",files="build.gradle[tags=filter-files]"]
====

The `filter()` method has two variants, which behave differently:

* one takes a `{javaApi}/java/io/FilterReader.html[FilterReader]` and is designed to work with Ant filters, such as `ReplaceTokens`
* one takes a closure or link:{javadocPath}/org/gradle/api/Transformer.html[Transformer] that defines the transformation for each line of the source file