code: def get_validator_by_name(
      name: str,
  ) -> Optional[type[base.BaseSQLValidator]]:
      return {
          "PrestoDBSQLValidator": presto_db.PrestoDBSQLValidator,
          "PostgreSQLValidator": postgres.PostgreSQLValidator,
      }.get(name)
  
imports: from typing import Optional
  from .None import base, postgres, presto_db
  from .base import SQLValidationAnnotation
label_desc: Use image node_id 1 for calling a global function with example usage: get_validator_by_name(name) and returns: dict