code: @Trivial
      static boolean isImmediateExpression(String expression, boolean mask) {
          final String methodName = "isImmediateExpression";
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) {
              Tr.entry(tc, methodName, new Object[] { (expression == null) ? null : mask ? OBFUSCATED_STRING : expression, mask });
          }
  
          boolean result = expression.startsWith("${") && expression.endsWith("}");
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) {
              Tr.exit(tc, methodName, result);
          }
          return result;
      }
docs: Return whether the expression is an immediate EL expression.
  
  @param expression The expression to evaluate.
  @param mask Set whether to mask the expression and result. Useful for when passwords might be
  contained in either the expression or the result.
  @return True if the expression is an immediate EL expression.