HistogramExemplarSampler (Prometheus Java Simpleclient 0.15.0 API)

All Known Subinterfaces:

ExemplarSampler

All Known Implementing Classes:

DefaultExemplarSampler
```
public interface HistogramExemplarSampler
```
Exemplar sampler for histogram metrics.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Exemplar`	`sample(double value, double bucketFrom, double bucketTo, Exemplar previous)`

- Method Detail
  - sample
```
Exemplar sample(double value,
                double bucketFrom,
                double bucketTo,
                Exemplar previous)
```
    Parameters:
    
    value - the value to be observed.
    
    bucketFrom - upper boundary of the previous bucket in the histogram. Will be Double.NEGATIVE_INFINITY if there is no previous bucket.
    
    bucketTo - upper boundary of this histogram bucket. Will be Double.POSITIVE_INFINITY if this is the last bucket.
    
    previous - the previously sampled exemplar, or null if there is none.
    
    Returns:
    
    an Exemplar to be sampled, or null if the previous exemplar does not need to be updated. Returning null and returning previous is equivalent.