docs: private String resolveExpressionString(final String unresolvedString) throws OperationFailedException {
  
          // parseAndResolve should only be providing expressions with no leading or trailing chars
          assert unresolvedString.startsWith("${") && unresolvedString.endsWith("}");
  
          // Default result is no change from input
          String result = unresolvedString;
  
          ModelNode resolveNode = new ModelNode(new ValueExpression(unresolvedString));
  
          // Try plug-in resolution; i.e. vault
          resolvePluggableExpression(resolveNode);
  
          if (resolveNode.getType() == ModelType.EXPRESSION ) {
              // resolvePluggableExpression did nothing. Try standard resolution
              String resolvedString = resolveStandardExpression(resolveNode);
              if (!unresolvedString.equals(resolvedString)) {
                  // resolveStandardExpression made progress
                  result = resolvedString;
              } // else there is nothing more we can do with this string
          } else {
              // resolvePluggableExpression made progress
              result = resolveNode.asString();
          }
  
          return result;
      }