docs: public static boolean isVariableNamePartValid( String namePart, Scope scope ) {
          if ( DIGITS_PATTERN.matcher(namePart).matches() ) {
              return true;
          }
          if ( REUSABLE_KEYWORDS.contains(namePart) ) {
              return scope.followUp(namePart, true);
          }
          return isVariableNameValid(namePart);
      }