@Test
  public void testMultipleColumnPrefixFilter() throws IOException {
    String filterString = " MultipleColumnPrefixFilter('qualifier1', 'qualifier2' ) ";
    MultipleColumnPrefixFilter multipleColumnPrefixFilter =
      doTestFilter(filterString, MultipleColumnPrefixFilter.class);
    byte[][] prefixes = multipleColumnPrefixFilter.getPrefix();
    assertEquals("qualifier1", new String(prefixes[0], StandardCharsets.UTF_8));
    assertEquals("qualifier2", new String(prefixes[1], StandardCharsets.UTF_8));
  }
This class tests ParseFilter.java It tests the entire work flow from when a string is given by
the user and how it is parsed to construct the corresponding Filter object
hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestParseFilter.java