OpenMetrics parser cannot parse the output of `promtool tsdb dump-openmetrics`

I tried using the example code...

import sys
from prometheus_client.openmetrics.parser import text_string_to_metric_families

for family in text_string_to_metric_families(sys.stdin.read()):
  for sample in family.samples:
      print("Name: {0} Labels: {1} Value: {2} Timestamp: {3}".format(*sample))

...to parse an OpenMetrics file produced by promtool tsdb dump-openmetrics, but I run into the following issue:

Traceback (most recent call last):
  File "/home/nicolas/IE6/synapse-meshsim/exp/./normalise_timestamps.py", line 6, in <module>
    for family in text_string_to_metric_families(sys.stdin.read()):
  File "/home/nicolas/IE6/synapse-meshsim/exp/venv/lib/python3.11/site-packages/prometheus_client/openmetrics/parser.py", line 18, in text_string_to_metric_families
    yield from text_fd_to_metric_families(StringIO.StringIO(text))
  File "/home/nicolas/IE6/synapse-meshsim/exp/venv/lib/python3.11/site-packages/prometheus_client/openmetrics/parser.py", line 543, in text_fd_to_metric_families
    yield build_metric(name, documentation, typ, unit, samples)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nicolas/IE6/synapse-meshsim/exp/venv/lib/python3.11/site-packages/prometheus_client/openmetrics/parser.py", line 472, in build_metric
    raise ValueError("Clashing name: " + name + suffix)
ValueError: Clashing name: go_gc_duration_seconds

This comes from this code: https://github.com/prometheus/client_python/blob/46eae7bae88f76951f7246d9f359f2dd5eeff110/prometheus_client/openmetrics/parser.py#L487-L489

But I don't understand why this check exists in the first place? In my case, I have the same metrics for multiple instances, and dump-openmetrics groups them by instance, then by metrics name. Can't we just remove this check altogether?

Start with prometheus_client/openmetrics/parser.py at the linked build_metric check and compare its assumptions with the grouped output from promtool tsdb dump-openmetrics. Reproduce the failure using the example parser code and that output. Done means the parser's behavior for repeated metric names is defined and the reported clashing-name failure is addressed.