class_docstr: This handler handles connection and execution of the Vertica statements.
class_docstr_tok: ["This","handler","handles","connection","and","execution","of","the","Vertica","statements","."]
code: def disconnect(self):
      if self.is_connected is False:
          return
      self.connection.close()
      self.is_connected = False
      return
  
imports: from collections import OrderedDict
  from typing import Optional
  import pandas
  import vertica_python
  from mindsdb_sql import parse_sql
  from mindsdb_sql.render.sqlalchemy_render import SqlalchemyRender
  from mindsdb_sql.parser.ast.base import ASTNode
  from mindsdb.utilities import log
  from mindsdb.integrations.libs.base import DatabaseHandler
  from mindsdb.integrations.libs.response import HandlerStatusResponse, HandlerResponse, RESPONSE_TYPE
  from mindsdb.integrations.libs.const import HANDLER_CONNECTION_ARG_TYPE
  from sqla_vertica_python.vertica_python import VerticaDialect
label_desc: Use image node_id 3 for calling the VerticaHandler obj's underlying member method code with example usage: obj.disconnect() without return types