class_docstr: Collection of InputToIssueSetMappingItems.
  
  This implements Sized to aid mf_pformat(). Sized is used in mf_pformat() when excluding display of empty items.
class_docstr_tok: ["Collection","of","InputToIssueSetMappingItems",".","This","implements","Sized","to","aid","mf_pformat","(",")",".","Sized","is","used","in","mf_pformat","(",")","when","excluding","display","of","empty","items","."]
docstr: Return an issue set that contains all issues in the included mapping items.
docstr_tok: ["Return","an","issue","set","that","contains","all","issues","in","the","included","mapping","items","."]
code: def merged_issue_set(self) -> MetricFlowQueryResolutionIssueSet:
      """Return an issue set that contains all issues in the included mapping items."""
      return MetricFlowQueryResolutionIssueSet.merge_iterable(
          item.issue_set for item in self.items
      )
  
imports: from __future__ import annotations
  from dataclasses import dataclass
  from typing import Optional, Sized, Tuple
  from typing_extensions import override
  from metricflow.collection_helpers.merger import Mergeable
  from metricflow.mf_logging.pretty_print import mf_pformat
  from metricflow.query.group_by_item.filter_spec_resolution.filter_spec_lookup import FilterSpecResolutionLookUp
  from metricflow.query.group_by_item.resolution_dag.dag import GroupByItemResolutionDag
  from metricflow.query.issues.issues_base import MetricFlowQueryResolutionIssueSet
  from metricflow.query.resolver_inputs.base_resolver_inputs import MetricFlowQueryResolverInput
  from metricflow.specs.specs import MetricFlowQuerySpec
label_desc: Use image node_id 2 for calling the InputToIssueSetMapping obj's underlying member method code with example usage: obj.merged_issue_set() and returns: MetricFlowQueryResolutionIssueSet