Clock (OpenTelemetry SDK Common)

```
@ThreadSafe
public interface Clock
```
Interface for getting the current time.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`long`	`nanoTime()`	Returns a time measurement with nanosecond precision that can only be used to calculate elapsed time.
`long`	`now()`	Obtains the current epoch timestamp in nanos from this clock.

- Method Detail
  - now
```
long now()
```
    Obtains the current epoch timestamp in nanos from this clock.
    
    Returns:
    
    the current epoch timestamp in nanos.
  - nanoTime
```
long nanoTime()
```
    Returns a time measurement with nanosecond precision that can only be used to calculate elapsed time.
    
    Returns:
    
    a time measurement with nanosecond precision that can only be used to calculate elapsed time.