Facebook Open Graph Object issue

FBSDKShareOpenGraphObject *object = [FBSDKShareOpenGraphObject objectWithProperties:@{@"og:type":@"xyz:metre", @"og:title"                    : @"metre title",  @"go:description" : @"metre desc",  @"og:quantity:value" : @7,  @"og:quantity:units" : @"m",  @"xyz:distance:value" : @5,  @"xyz:distance:units" : @"m"}];

  FBSDKShareOpenGraphAction *action = [[FBSDKShareOpenGraphAction alloc] init];
  action.actionType = @"xyz:travel";
  [action setObject:object forKey:@"travel:metre"];

  FBSDKShareOpenGraphContent *content = [[FBSDKShareOpenGraphContent alloc] init];
  content.action = action;
  content.previewPropertyName = @"travel:metre";

  [FBSDKShareAPI shareWithContent:content delegate:self];
}`