metrics histogram example

[esigo]

Adds metrics histogram example.

Changes

Please provide a brief description of the changes here.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[codecov]

Codecov Report

Merging #1330 (c1181b2) into main (1d2cd42) will not change coverage.
The diff coverage is n/a.

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  Coverage   91.89%   91.89%           
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  Files         217      217           
  Lines        7922     7922           
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  Hits         7279     7279           
  Misses        643      643           

[lalitb]

Thanks for adding the support. LGTM with minor comments.

[lalitb]

May be as an enhancement later, just like val, we can also have random attributes passed. Define 4-5 kv-attributes, select one of them randomly, and pass in Record method.

[esigo]

thanks, added random attribute.

[lalitb]

Would also be a good use-case to create both counter and histogram if no argument is specified - to demonstrate getting metrics from multiple instruments simultaneously.

[esigo]

thanks, added multiple instruments simultaneously.