Instruction (bgpcep 0.15.5-SNAPSHOT API)

```
public interface Instruction
```

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`checkedExecutionStart()`	Instruction executors are required to call this method prior to starting executing on the instruction.
`void`	`executionCompleted(InstructionStatus status, Details details)`	Instruction executors are required to call this method when execution has finished to provide the execution result to the end.
`boolean`	`executionHeldUp(Details details)`	Instruction executors can inform about execution hold ups which prevent an otherwise-ready instruction from executing by calling this method.

- Method Detail
  - checkedExecutionStart
```
boolean checkedExecutionStart()
```
    Instruction executors are required to call this method prior to starting executing on the instruction. Implementations of this method are required to transition into Executing state and return true, or into Cancelled state and return false.
    
    Returns:
    
    Indication whether the instruction execution should proceed.
  - executionHeldUp
```
boolean executionHeldUp(Details details)
```
    Instruction executors can inform about execution hold ups which prevent an otherwise-ready instruction from executing by calling this method. It is recommended they check the return of this method to detect if a cancellation occurred asynchronously.
    
    Parameters:
    
    details - Details which execution is held up
    
    Returns:
    
    Indication whether the instruction execution should proceed. If this method returns false, all subsequent calls to this method as well as checkedExecutionStart() will return false.
  - executionCompleted
```
void executionCompleted(InstructionStatus status,
                        Details details)
```
    Instruction executors are required to call this method when execution has finished to provide the execution result to the end.
    
    Parameters:
    
    status - Execution result
    
    details - Execution result details