* @return a {@code CharSource} containing the concatenated data
   * @since 15.0
   */
  public static CharSource concat(Iterable<? extends CharSource> sources) {
    return new ConcatenatedCharSource(sources);
  }

  /**
   * Concatenates multiple {@link CharSource} instances into a single source. Streams returned from
   * the source will contain the concatenated data from the streams of the underlying sources.
   *

The function does the following:

* Takes a `first_name` and `last_name`.
* Converts the first letter of each one to upper case with `title()`.
* <dfn title="Puts them together, as one. With the contents of one after the other.">Concatenates</dfn> them with a space in the middle.

{* ../../docs_src/python_types/tutorial001_py310.py hl[2] *}

### Edit it { #edit-it }

It's a very simple program.

      @Override
      public Iterator<T> iterator() {
        return Iterators.concat(Iterators.transform(inputs.iterator(), Iterable::iterator));
      }
    };
  }

  /** Concatenates a varargs array of iterables without making a defensive copy of the array. */
  private static <T extends @Nullable Object> FluentIterable<T> concatNoDefensiveCopy(
      Iterable<? extends T>... inputs) {

      @Override
      public Iterator<T> iterator() {
        return Iterators.concat(Iterators.transform(inputs.iterator(), Iterable::iterator));
      }
    };
  }

  /** Concatenates a varargs array of iterables without making a defensive copy of the array. */
  private static <T extends @Nullable Object> FluentIterable<T> concatNoDefensiveCopy(
      Iterable<? extends T>... inputs) {

	}

	// Create subslices from recorded field indices.
	a := make([][]byte, len(spans))
	for i, span := range spans {
		a[i] = s[span.start:span.end:span.end]
	}

	return a
}

// Join concatenates the elements of s to create a new byte slice. The separator
// sep is placed between elements in the resulting slice.
func Join(s [][]byte, sep []byte) []byte {
	if len(s) == 0 {
		return []byte{}
	}

    return Arrays.copyOf(empty, length);
  }

  /**
   * Returns a new array that contains the concatenated contents of two arrays.
   *
   * @param first the first array of elements to concatenate
   * @param second the second array of elements to concatenate
   * @param type the component type of the returned array
   */
  @GwtIncompatible // Array.newInstance(Class, int)

    return Arrays.copyOf(empty, length);
  }

  /**
   * Returns a new array that contains the concatenated contents of two arrays.
   *
   * @param first the first array of elements to concatenate
   * @param second the second array of elements to concatenate
   * @param type the component type of the returned array
   */
  @GwtIncompatible // Array.newInstance(Class, int)

   * position + 8. The array must have at least 8 bytes from offset (inclusive).
   *
   * @param input the input bytes
   * @param offset the offset into the array at which to start
   * @return a long of a concatenated 8 bytes
   */
  static long load64(byte[] input, int offset) {
    // We don't want this in production code as this is the most critical part of the loop.
    assert input.length >= offset + 8;

    CharSource concatenated = CharSource.concat(cycle);

    String expected = "abcdabcd";

    // read the first 8 chars manually, since there's no equivalent to ByteSource.slice
    // TODO(cgdecker): Add CharSource.slice?
    StringBuilder builder = new StringBuilder();
    Reader reader = concatenated.openStream(); // no need to worry about closing

    ByteSource source = ByteSource.wrap(new byte[] {0, 1, 2, 3});
    Iterable<ByteSource> cycle = Iterables.cycle(ImmutableList.of(source));
    ByteSource concatenated = ByteSource.concat(cycle);

    byte[] expected = {0, 1, 2, 3, 0, 1, 2, 3};
    assertArrayEquals(expected, concatenated.slice(0, 8).read());
  }

  private static final ByteSource BROKEN_CLOSE_SOURCE =
      new TestByteSource(new byte[10], CLOSE_THROWS);