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

 * @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.
     *

Guillaume Nodet <******@****.***> 1729859506 +0200

    val source2 = relay.newSource()!!.buffer()
    assertThat(source1.readUtf8(5)).isEqualTo("abcde")
    assertThat(source2.readUtf8(5)).isEqualTo("abcde")
    assertThat(source2.readUtf8(5)).isEqualTo("fghij")
    assertThat(source1.readUtf8(5)).isEqualTo("fghij")
    assertThat(source1.exhausted()).isTrue()
    assertThat(source2.exhausted()).isTrue()
    source1.close()
    source2.close()
    assertThat(relay.isClosed).isTrue()

        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();
        }

   * 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.
   *

        // merge implicitly assumes that merge is only called on the same GAV and does not perform any validation here!
        Metadata source = new Metadata();
        source.setArtifactId("source-artifact");
        source.setGroupId("source-group");
        source.setVersion("2.0");
        assertFalse(target.merge(source));
        assertEquals("myArtifact", target.getArtifactId());
        assertEquals("myGroup", target.getGroupId());

     * @throws RuntimeException If failed (and not due source not exists).
     */
    boolean get(@Nonnull URI relativeSource, @Nonnull Path target);

    /**
     * GETs the source URI content as byte array. The source MUST BE relative from the {@link RemoteRepository#getUrl()}
     * root.
     *
     * @return the byte array if operation succeeded, {@code null} if source does not exist.

  }

  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));

  }

  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));