
 
        Determines the criticality of the LDAP control.
 A critical control must not be ignored by the server.
 In other words, if the server receives a critical control
 that it does not support, regardless of whether the control
 makes sense for the operation, the operation will not be performed
 and an 
OperationNotSupportedException will be thrown.
        
        
Returns:
    true if this control is critical; false otherwise.