class_docstr: A tracker for Weights and Biases.
  
  Note that you have to perform wandb login beforehand.
class_docstr_tok: ["A","tracker","for","Weights","and","Biases",".","Note","that","you","have","to","perform","wandb","login","beforehand","."]
code: def log_metrics(
      self,
      metrics: Mapping[str, float],
      step: Optional[int] = None,
      prefix: Optional[str] = None,
  ) -> None:  # noqa: D102
      if self.run is None:
          raise AssertionError(
              "start_run must be called before logging any metrics"
          )
      metrics = flatten_dictionary(dictionary=metrics, prefix=prefix)
      self.run.log(metrics, step=step)
  
file_path: pykeen/src/pykeen/trackers/wandb.py
imports: import os
  from typing import TYPE_CHECKING, Any, Mapping, Optional
  from .base import ResultTracker
  from ..utils import flatten_dictionary
label_desc: Use image node_id 4 for calling the WANDBResultTracker obj's underlying member method code with example usage: obj.log_metrics(metrics, step, prefix) without return types