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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def trigger_installed(connection: connection, table: str, schema: str='public'):
 """Test whether or not a psycopg2-pgevents trigger is installed for a table. Parameters connection: psycopg2.extensions.connection Active connection to a PostGreSQL database. table: str Table whose trigger-existence will be checked. schema: str Schema to which the table belongs. Returns ------- bool True if the trigger is installed, otherwise False. """

    installed = False

    log('Checking if {}.{} trigger installed...'.format(schema, table), logger_name=_LOGGER_NAME)

    statement = SELECT_TRIGGER_STATEMENT.format(
        table=table,
        schema=schema
    )

    result = execute(connection, statement)
    if result:
        installed = True

    log('...{}installed'.format('' if installed else 'NOT '), logger_name=_LOGGER_NAME)

    return installed