code: @Override
  	public AuthorizationRequest checkForPreApproval(AuthorizationRequest authorizationRequest,
  			Authentication userAuthentication) {
  
  		boolean approved = false;
  		// If we are allowed to check existing approvals this will short circuit the decision
  		if (useApprovalStore) {
  			authorizationRequest = super.checkForPreApproval(authorizationRequest, userAuthentication);
  			approved = authorizationRequest.isApproved();
  		}
  		else {
  			if (clientDetailsService != null) {
  				Collection<String> requestedScopes = authorizationRequest.getScope();
  				try {
  					ClientDetails client = clientDetailsService
  							.loadClientByClientId(authorizationRequest.getClientId());
  					for (String scope : requestedScopes) {
  						if (client.isAutoApprove(scope)) {
  							approved = true;
  							break;
  						}
  					}
  				}
  				catch (ClientRegistrationException e) {
  				}
  			}
  		}
  		authorizationRequest.setApproved(approved);
  
  		return authorizationRequest;
  
  	}
docs: Allows automatic approval for a white list of clients in the implicit grant case.
  
  @param authorizationRequest The authorization request.
  @param userAuthentication the current user authentication
  
  @return An updated request if it has already been approved by the current user.