@Test
  public void testIncorrectCompareOperator() throws IOException {
    String filterString = "RowFilter ('>>' , 'binary:region')";
    try {
      doTestFilter(filterString, RowFilter.class);
      assertTrue(false);
    } catch (IllegalArgumentException e) {
      System.out.println("Incorrect compare operator >>");
    }
  }
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