class_docstr: Rule engine to processes rules
class_docstr_tok: ["Rule","engine","to","processes","rules"]
docstr: Returns TRUE if the requested publisher is valid (a string name or reference)
docstr_tok: ["Returns","TRUE","if","the","requested","publisher","is","valid","(","a","string","name","or","reference",")"]
code: def is_publisher_declaration(cls, string_or_reference):
      """Returns TRUE if the requested publisher is valid (a string name or reference)"""
      return isinstance(
          string_or_reference, str
      ) or AlertPublisherRepository.is_valid_publisher(
          string_or_reference
      )
  
imports: from datetime import datetime, timedelta
  from os import environ
  from streamalert.shared.publisher import AlertPublisherRepository
  from streamalert.rules_engine.alert_forwarder import AlertForwarder
  from streamalert.rules_engine.threat_intel import ThreatIntel
  from streamalert.shared import resources, RULES_ENGINE_FUNCTION_NAME
  from streamalert.shared.alert import Alert
  from streamalert.shared.config import load_config
  from streamalert.shared.importer import import_folders
  from streamalert.shared.logger import get_logger
  from streamalert.shared.lookup_tables.core import LookupTables
  from streamalert.shared.metrics import MetricLogger
  from streamalert.shared.rule import Rule
  from streamalert.shared.rule_table import RuleTable
  from streamalert.shared.stats import RuleStatisticTracker
label_desc: Use image node_id 15 for calling the RulesEngine obj's underlying member method code with example usage: obj.is_publisher_declaration(cls, string_or_reference) and returns: unknown