* Returns a view of a slice of this byte source that is at most {@code length} bytes long
   * starting at the given {@code offset}. If {@code offset} is greater than the size of this
   * source, the returned source will be empty. If {@code offset + length} is greater than the size
   * of this source, the returned source will contain the slice starting at {@code offset} and
   * ending at the end of this source.
   *

                  <fileset dir="${project.build.directory}/guava-sources">
                    <include name="**/ListenableFuture.java" />
                  </fileset>
                </copy>
                <copy toDir="${project.build.directory}/guava-gwt-sources">
                  <fileset dir="${project.build.directory}/failureaccess-sources">

import java.io.File;
import java.io.IOException;

/**
 * A test factory for byte or char sources or sinks. In addition to creating sources or sinks, the
 * factory specifies what content should be expected to be read from a source or contained in a sink
 * given the content data that was used to create the source or that was written to the sink.
 *

        if (!source.isEmpty()) {
          return false;
        }
      }
      return true;
    }

    @Override
    public Optional<Long> lengthIfKnown() {
      long result = 0L;
      for (CharSource source : sources) {
        Optional<Long> lengthIfKnown = source.lengthIfKnown();
        if (!lengthIfKnown.isPresent()) {
          return Optional.absent();
        }

        if (!source.isEmpty()) {
          return false;
        }
      }
      return true;
    }

    @Override
    public Optional<Long> lengthIfKnown() {
      long result = 0L;
      for (CharSource source : sources) {
        Optional<Long> lengthIfKnown = source.lengthIfKnown();
        if (!lengthIfKnown.isPresent()) {
          return Optional.absent();
        }

 * interface easier to implement for certain types of data sources.
 *
 * <p>{@code Iterator} requires its implementations to support querying the end-of-data status
 * without changing the iterator's state, using the {@link #hasNext} method. But many data sources,
 * such as {@link java.io.Reader#read()}, do not expose this information; the only way to discover

   * Returns a view of a slice of this byte source that is at most {@code length} bytes long
   * starting at the given {@code offset}. If {@code offset} is greater than the size of this
   * source, the returned source will be empty. If {@code offset + length} is greater than the size
   * of this source, the returned source will contain the slice starting at {@code offset} and
   * ending at the end of this source.
   *

        <executions>
          <execution>
            <id>add-benchmark-sources</id>
            <phase>generate-test-sources</phase>
            <goals><goal>add-test-source</goal></goals>
            <configuration>
              <sources>
                <source>benchmark</source>
              </sources>
            </configuration>
          </execution>
        </executions>
      </plugin>

    List<ByteSource> sources = Lists.newArrayList();
    int start = 0;
    for (Integer span : spans) {
      sources.add(newByteSource(start, span));
      start += span;
    }
    ByteSource joined = ByteSource.concat(sources);
    assertTrue(newByteSource(0, start).contentEquals(joined));
  }

  public void testReadSingleByte() throws Exception {
    ByteSource source = newByteSource(0, 10);

 * and files.
 *
 * <p>At the core of this package are the Source/Sink types: {@link ByteSource ByteSource}, {@link
 * CharSource CharSource}, {@link ByteSink ByteSink} and {@link CharSink CharSink}. They are
 * factories for I/O streams that provide many convenience methods that handle both opening and
 * closing streams for you.
 *
 * <p>This package is a part of the open-source <a href="https://github.com/google/guava">Guava</a>