# Interface: com.pnfsoftware.jeb.util.collect.VerifiedDeque.FailureHandler

Failure handler for [VerifiedDeque](VerifiedDeque).

## Method: inBlacklist
- parameter: `e`, type: `E`
- return type: `int`

Description: 
parameter: e: the element to be added is in the provided black\-list
return: 0=do not insert; 1=insert anyway; \-1= failure \(throw\)

## Method: notInWhitelist
- parameter: `e`, type: `E`
- return type: `int`

Description: 
parameter: e: the element to be added is not in the provided white\-list
return: 0=do not insert; 1=insert anyway; \-1= failure \(throw\)