she first saw the White Rabbit.  She was a little nervous about
it just at first, the two creatures got so close to her, one on
each side, and opened their eyes and mouths so VERY wide, but she
gained courage as she went on.  Her listeners were perfectly
quiet till she got to the part about her repeating `YOU ARE OLD,
FATHER WILLIAM,' to the Caterpillar, and the words all coming

    bufferHelper("no newlines at all", "no newlines at all");
    bufferHelper("two lines\nbut no newline at end", "two lines\n", "but no newline at end");
    bufferHelper(
        "\nempty first line\nno newline at end", "\n", "empty first line\n", "no newline at end");
    bufferHelper("three\rlines\rno newline at end", "three\r", "lines\r", "no newline at end");
    bufferHelper("mixed\nline\rendings\r\n", "mixed\n", "line\r", "endings\r\n");

    if (r instanceof Reader) {
      copyReaderToBuilder((Reader) r, sb);
    } else {
      copy(r, sb);
    }
    return sb;
  }

  /**
   * Reads all of the lines from a {@link Readable} object. The lines do not include
   * line-termination characters, but do include other leading and trailing whitespace.
   *
   * <p>Does not close the {@code Readable}. If reading files or resources you should use the {@link

  }

  /**
   * Streams lines from a {@link File}, stopping when our callback returns false, or we have read
   * all of the lines.
   *
   * @param file the file to read from
   * @param charset the charset used to decode the input stream; see {@link StandardCharsets} for
   *     helpful predefined constants
   * @param callback the {@link LineProcessor} to use to handle the lines
   * @return the output of processing the lines

  }

  /**
   * Returns a splitter that considers any subsequence matching {@code pattern} to be a separator.
   * For example, {@code Splitter.on(Pattern.compile("\r?\n")).split(entireFile)} splits a string
   * into lines whether it uses DOS-style or UNIX-style line terminators.
   *
   * @param separatorPattern the pattern that determines whether a subsequence is a separator. This
   *     pattern may not match the empty string.

     * --- System.out.println(input + " " + simplifyPath(input));
     * --- fail(). (If the test were to pass, its output would be hidden.)
     * - Run the test.
     * - Pull the relevant lines of output from the test into a testcases file.
     * - Test the output:
     * --- cat testcases | while read L; do
     *       X=($L)
     *       A=$( cd /b/c && sudo mkdir -p ${X[0]} && cd ${X[0]} && pwd |

     * --- System.out.println(input + " " + simplifyPath(input));
     * --- fail(). (If the test were to pass, its output would be hidden.)
     * - Run the test.
     * - Pull the relevant lines of output from the test into a testcases file.
     * - Test the output:
     * --- cat testcases | while read L; do
     *       X=($L)
     *       A=$( cd /b/c && sudo mkdir -p ${X[0]} && cd ${X[0]} && pwd |

    }
    reader.close();
    writer.close();

    assertExpectedString(writer.toString());
  }

  public void testLines() throws IOException {
    try (Stream<String> lines = source.lines()) {
      assertExpectedLines(lines.collect(toImmutableList()));
    }
  }

  public void testCopyTo_appendable() throws IOException {
    StringBuilder builder = new StringBuilder();

   */
  @CanIgnoreReturnValue // some uses know that their processor never returns false
  boolean processLine(String line) throws IOException;

  /** Return the result of processing all the lines. */
  @ParametricNullness
  T getResult();

  }

  /**
   * Returns a splitter that considers any subsequence matching {@code pattern} to be a separator.
   * For example, {@code Splitter.on(Pattern.compile("\r?\n")).split(entireFile)} splits a string
   * into lines whether it uses DOS-style or UNIX-style line terminators.
   *
   * @param separatorPattern the pattern that determines whether a subsequence is a separator. This
   *     pattern may not match the empty string.