class_docstr: Beam DoFn class that reads from Presto.
  
  Attributes:
    cursor: A prestodb.dbapi.Cursor object that reads records from Presto table.
class_docstr_tok: ["Beam","DoFn","class","that","reads","from","Presto",".","Attributes",":","cursor",":","A","prestodb.dbapi.Cursor","object","that","reads","records","from","Presto","table","."]
code: def teardown(self):
      if self.cursor:
          self.cursor.close()
  
imports: import datetime
  from typing import Any, Dict, Iterable, Tuple
  import apache_beam
  import prestodb
  import tensorflow
  from tfx.components.example_gen import base_example_gen_executor
  from tfx.examples.custom_components.presto_example_gen.proto import presto_config_pb2
  from tfx.proto import example_gen_pb2
  from tfx.utils import proto_utils
label_desc: Use image node_id 3 for calling the _ReadPrestoDoFn obj's underlying member method code with example usage: obj.teardown() without return types