code: def test_stream_case(self):
      from pyflink.shell import s_env, st_env, DataTypes
      from pyflink.table.schema import Schema
      from pyflink.table.table_descriptor import (
          TableDescriptor,
          FormatDescriptor,
      )
  
      # example begin
  
      import tempfile
      import os
      import shutil
  
      sink_path = tempfile.gettempdir() + "/streaming.csv"
      if os.path.exists(sink_path):
          if os.path.isfile(sink_path):
              os.remove(sink_path)
          else:
              shutil.rmtree(sink_path)
      s_env.set_parallelism(1)
      t = st_env.from_elements(
          [(1, "hi", "hello"), (2, "hi", "hello")], ["a", "b", "c"]
      )
  
      st_env.create_temporary_table(
          "stream_sink",
          TableDescriptor.for_connector("filesystem")
          .schema(
              Schema.new_builder()
              .column("a", DataTypes.BIGINT())
              .column("b", DataTypes.STRING())
              .column("c", DataTypes.STRING())
              .build()
          )
          .option("path", sink_path)
          .format(
              FormatDescriptor.for_format("csv")
              .option("field-delimiter", ",")
              .build()
          )
          .build(),
      )
  
      from pyflink.table.expressions import col
  
      t.select(col("a") + 1, col("b"), col("c")).execute_insert(
          "stream_sink"
      ).wait()
  
      # verify code, do not copy these code to shell.py
      with open(
          os.path.join(sink_path, os.listdir(sink_path)[0]), "r"
      ) as f:
          lines = f.read()
          self.assertEqual(lines, "2,hi,hello\n" + "3,hi,hello\n")
  
label_desc: Use image node_id 1 for calling the ShellExampleTests obj's underlying member method code with example usage: obj.test_stream_case() without return types