code: def test_seq_source(self):
      seq_source = NumberSequenceSource(1, 10)
  
      seq_source_clz = load_java_class(
          "org.apache.flink.api.connector.source.lib.NumberSequenceSource"
      )
      from_field = seq_source_clz.getDeclaredField("from")
      from_field.setAccessible(True)
      self.assertEqual(
          1, from_field.get(seq_source.get_java_function())
      )
  
      to_field = seq_source_clz.getDeclaredField("to")
      to_field.setAccessible(True)
      self.assertEqual(10, to_field.get(seq_source.get_java_function()))
  
imports: from pyflink.datastream.connectors.number_seq import NumberSequenceSource
  from pyflink.testing.test_case_utils import PyFlinkStreamingTestCase
  from pyflink.util.java_utils import load_java_class
label_desc: Use image node_id 1 for calling the SequenceSourceTests obj's underlying member method code with example usage: obj.test_seq_source() without return types