code: public static String stringifyScopeNames(Scope[] scopes)
      {
          if (scopes == null)
          {
              return null;
          }
  
          String[] array = new String[scopes.length];
  
          for (int i = 0; i < scopes.length; ++i)
          {
              array[i] = (scopes[i] == null) ? null : scopes[i].getName();
          }
  
          return join(array, " ");
      }
docs: Generate a list of scope names.
  
  @param scopes
  An array of {@link Scope}. If {@code null} is given,
  {@code null} is returned.
  
  @return
  A string containing scope names using white spaces as
  the delimiter.
  
  @since 2.5