core-android/src/main/java/com/uber/sdk/android/core/auth/AuthUtils.java
@NonNull
    public static String scopeCollectionToString(@NonNull Collection<Scope> scopes) {
        Set<String> stringSet = scopeCollectionToStringSet(scopes);
        return TextUtils.join(" ", stringSet).toLowerCase();
    }
@NonNull
    public static String scopeCollectionToString(@NonNull Collection<Scope> scopes) {
        Set<String> stringSet = scopeCollectionToStringSet(scopes);
        return TextUtils.join(" ", stringSet).toLowerCase();
    }
Converts a {@link Collection} of {@link Scope}s into a space-delimited {@link String}.

@param scopes the {@link Collection} of {@link Scope}s to convert
@return a space-delimited {@link String} of {@link Scope}s