code: def from_run(cls, run: "Run", metric: str) -> "LineKey":
      key = f"{run.id}:{metric}"
      return cls(key)
  
file_path: wandb/wandb/apis/reports/_helpers.py
imports: from typing import Optional
  from ..public import PanelMetricsHelper, Run
  from .runset import Runset
  from .util import Attr, Base, Panel, nested_get, nested_set
label_desc: Use image node_id 4 for calling the LineKey obj's underlying member method code with example usage: obj.from_run(cls, run, metric) and returns: cls