/**
     * Gets the user toolchains source.
     *
     * @return The user toolchains source or {@code null} if none.
     */
    Source getUserToolchainsSource();

    /**
     * Sets the user toolchains source. If both user toolchains and a global toolchains are given, the user toolchains
     * take precedence.
     *

                public class Source {
                    public Source(@Nullable String some) {}
                    @Nullable public String nonFinalField = null;
                    public String foo(@Nullable String bar) { return "some"; }
                }
            """,
            v2 = """
                public class Source {
                    public Source(String some) {}

        // 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());

        return builder(requireNonNull(request, "request cannot be null"))
                .source(requireNonNull(source, "source cannot be null"))
                .build();
    }

    @Nonnull
    static ModelBuilderRequest build(@Nonnull Session session, @Nonnull ModelSource source) {
        return builder()

    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());

	// S3 extensions
	AmzCopySourceIfModifiedSince   = "x-amz-copy-source-if-modified-since"
	AmzCopySourceIfUnmodifiedSince = "x-amz-copy-source-if-unmodified-since"

	AmzCopySourceIfNoneMatch = "x-amz-copy-source-if-none-match"
	AmzCopySourceIfMatch     = "x-amz-copy-source-if-match"

	AmzCopySource                 = "X-Amz-Copy-Source"
	AmzCopySourceVersionID        = "X-Amz-Copy-Source-Version-Id"

   * 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 sourceEndpoint == "" {
		log.Fatalln("source Endpoint is not provided")
	}

	if sourceAccessKey == "" {
		log.Fatalln("source Access key is not provided")
	}

	if sourceSecretKey == "" {
		log.Fatalln("source Secret key is not provided")
	}

	if sourceBucket == "" && sourcePrefix != "" {
		log.Fatalln("--source-prefix is specified without --source-bucket.")
	}

	if targetEndpoint == "" {

public interface Transport extends Closeable {
    /**
     * GETs the source URI content into target (does not have to exist, or will be overwritten if exist). The
     * source MUST BE relative from the {@link RemoteRepository#getUrl()} root.
     *
     * @return {@code true} if operation succeeded, {@code false} if source does not exist.
     * @throws RuntimeException If failed (and not due source not exists).
     */

	{
		Header: http.Header{
			"X-Amz-Copy-Source-Server-Side-Encryption-Customer-Algorithm": []string{""},
			"X-Amz-Copy-Source-Server-Side-Encryption-Customer-Key":       []string{""},
			"X-Amz-Copy-Source-Server-Side-Encryption-Customer-Key-Md5":   []string{""},
		},
		Expected: true,
	}, // 4
	{
		Header: http.Header{
			"X-Amz-Copy-Source-Server-Side-Encryption-Customer-Algorithm": []string{"AES256"},