class_docstr: Handles a ListSessionGroups request.
class_docstr_tok: ["Handles","a","ListSessionGroups","request","."]
docstr: Constructs lists of SessionGroups based on hparam tag metadata.
code: def _session_groups_from_tags(self):
      """Constructs lists of SessionGroups based on hparam tag metadata."""
      # Query for all Hparams summary metadata one time to minimize calls to
      # the underlying DataProvider.
      hparams_run_to_tag_to_content = (
          self._backend_context.hparams_metadata(
              self._request_context, self._experiment_id
          )
      )
      # Construct the experiment one time since an context.experiment() call
      # may search through all the runs.
      experiment = self._backend_context.experiment_from_metadata(
          self._request_context,
          self._experiment_id,
          self._include_metrics,
          hparams_run_to_tag_to_content,
          # Don't pass any information from the DataProvider since we are only
          # examining session groups based on tag metadata
          provider.ListHyperparametersResult(
              hyperparameters=[], session_groups=[]
          ),
      )
      extractors = _create_extractors(self._request.col_params)
      filters = _create_filters(self._request.col_params, extractors)
  
      session_groups = self._build_session_groups(
          hparams_run_to_tag_to_content, experiment.metric_infos
      )
      session_groups = self._filter(session_groups, filters)
      self._sort(session_groups, extractors)
  
      if _specifies_include(self._request.col_params):
          _reduce_to_hparams_to_include(
              session_groups, self._request.col_params
          )
  
      return session_groups
  
imports: import collections
  import dataclasses
  import operator
  import re
  from typing import Optional
  from google.protobuf import struct_pb2
  from tensorboard.data import provider
  from tensorboard.plugins.hparams import api_pb2
  from tensorboard.plugins.hparams import backend_context
  from tensorboard.plugins.hparams import error
  from tensorboard.plugins.hparams import json_format_compat
  from tensorboard.plugins.hparams import metadata
  from tensorboard.plugins.hparams import metrics
  from tensorboard.plugins.hparams import plugin_data_pb2
label_desc: Use image node_id 3 for calling the Handler obj's underlying member method code with example usage: obj._session_groups_from_tags() and returns: session_groups