### Question:
LrcUtil { public static String getEditor(String lrcString) { String pattern = "\\[by:(.*)\\]"; Pattern r = Pattern.compile(pattern); Matcher m = r.matcher(lrcString); if (m.find()) { return m.group(1); } else { return null; } }  static String getArtist(String lrcString); static String getTitle(String lrcString); static String getAlbum(String lrcString); static String getEditor(String lrcString); static String getOffset(String lrcString);  }### Answer:
@Test public void getEditor() { assertEquals("中文", LrcUtil.getEditor("[by:中文]")); assertEquals("1125", LrcUtil.getEditor("[by:1125]")); assertEquals("[1125]", LrcUtil.getEditor("[by:[1125]]")); assertEquals(null, LrcUtil.getEditor("[by1235]")); }