* @see org.apache.maven.api.services.ProjectBuilder#build(Session, Source)
 * @see org.apache.maven.api.services.SettingsBuilder#build(Session, Source, Source, Source)
 * @see org.apache.maven.api.services.ToolchainsBuilder#build(Session, Source, Source)
 */
@Experimental
public interface Source {

    /**
     * Provides access the file to be parsed, if this source is backed by a file.
     *

import java.io.InputStream;

/**
 * Provides access to the contents of a source independently of the backing store (e.g. file system, database, memory).
 *
 */
public interface Source {

    /**
     * Gets a byte stream to the source contents. Closing the returned stream is the responsibility of the caller.
     *
     * @return A byte stream to the source contents, never {@code null}.
     * @throws IOException in case of IO issue

  }

  public void testContentEquals() throws IOException {
    assertTrue(source.contentEquals(source));
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());

    ByteSource equalSource = new TestByteSource(bytes);
    assertTrue(source.contentEquals(equalSource));
    assertTrue(new TestByteSource(bytes).contentEquals(source));

    assertEquals(STRING.length(), source.copyTo(sink));
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());
    assertTrue(sink.wasStreamOpened() && sink.wasStreamClosed());

    assertEquals(STRING, sink.getString());
  }

  public void testRead_toString() throws IOException {
    assertEquals(STRING, source.read());
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());
  }

   * 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.
   *

        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();
        }

     * @param source the source location
     * @param sourceDominant the boolean indicating of {@code source} is dominant compared to {@code target}
     * @return the merged location
     */
    public static InputLocation merge(InputLocation target, InputLocation source, boolean sourceDominant) {
        if (source == null) {
            return target;
        } else if (target == null) {
            return source;
        }

    /**
     * Gets the global Toolchains source.
     *
     * @return the global Toolchains source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getGlobalToolchainsSource();

    /**
     * Gets the user Toolchains source.
     *
     * @return the user Toolchains source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getUserToolchainsSource();

    @Nonnull

        IllegalArgumentException.class,
        () -> source.slice(0, -1));
  }

  // Test that you can not expand the readable data in a previously sliced ByteSource.
  public void testSlice_constrainedRange() throws IOException {
    long size = source.read().length;
    if (size >= 2) {
      ByteSource sliced = source.slice(1, size - 2);
      assertEquals(size - 2, sliced.read().length);

    assertEquals(testString.length() * 3, result.length());
  }

  public void testReady() throws Exception {
    CharSource source = newCharSource("a");
    Iterable<? extends CharSource> list = ImmutableList.of(source, source);
    Reader joinedReader = CharSource.concat(list).openStream();

    assertTrue(joinedReader.ready());
    assertEquals('a', joinedReader.read());