code: def observe(self, metric_name, value, echo=False):
      histogram = self.histograms.get(metric_name)
      if histogram is None:
          logging.warning(f"No such Histogram: {metric_name}")
          return
      histogram.observe(value)
      if echo:
          logging.info(f"{metric_name} {value}")
  
file_path: ray/python/ray/experimental/raysort/tracing_utils.py
imports: import datetime
  import functools
  import logging
  import time
  from typing import List, Tuple
  import ray
  from ray.experimental.raysort import constants, logging_utils
  from ray.util.metrics import Gauge, Histogram
label_desc: Use image node_id 5 for calling the ProgressTracker obj's underlying member method code with example usage: obj.observe(metric_name, value, echo) without return types