Return an iterator positioned at the beginning of the sequence of MetricSampleGroup objects contained by this object. Note that the iterator will remain valid until this sample is modified by invoking either appendGroups or removeAllRecords().
MetricSampleGroup
appendGroups
removeAllRecords()
Declared in <balm_metricsample.h>
<balm_metricsample.h>
MetricSample::const_iterator begin() const;