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As per apple documentation I go through them, after surfing I didn't get any of the basic implementation for electrocardio gram steps: Request Permission. Reading the values for data points. Sample query. Also need to understand, how this is different from HKCategoryTypeIdentifier/HKQuantityTypeIdentifier. As in other heakthdata points the above identifier is used to formulate the data point accessing and reading and adding into our local storage. Any sugesstion please.