class_docstr: CustomScalars Plugin for TensorBoard.
code: def frontend_metadata(self):
      return base_plugin.FrontendMetadata(
          element_name="tf-custom-scalar-dashboard",
          tab_name="Custom Scalars",
      )
  
imports: import re
  from google.protobuf import json_format
  from werkzeug import wrappers
  from tensorboard import plugin_util
  from tensorboard.backend import http_util
  from tensorboard.compat import tf
  from tensorboard.data import provider
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.custom_scalar import layout_pb2
  from tensorboard.plugins.custom_scalar import metadata
  from tensorboard.plugins.scalar import metadata
  from tensorboard.plugins.scalar import scalars_plugin
label_desc: Use image node_id 5 for calling the CustomScalarsPlugin obj's underlying member method code with example usage: obj.frontend_metadata() and returns: base_plugin