guava/src/com/google/common/io/LineBuffer.java
@CanIgnoreReturnValue
  private boolean finishLine(boolean sawNewline) throws IOException {
    String separator = sawReturn ? (sawNewline ? "\r\n" : "\r") : (sawNewline ? "\n" : "");
    handleLine(line.toString(), separator);
    line = new StringBuilder();
    sawReturn = false;
    return sawNewline;
  }
@CanIgnoreReturnValue
  private boolean finishLine(boolean sawNewline) throws IOException {
    String separator = sawReturn ? (sawNewline ? "\r\n" : "\r") : (sawNewline ? "\n" : "");
    handleLine(line.toString(), separator);
    line = new StringBuilder();
    sawReturn = false;
    return sawNewline;
  }
Called when a line is complete.