code: public static boolean isValidJsonValue( Object value ) {
        if( JSONNull.getInstance()
              .equals( value ) || value instanceof JSON || value instanceof Boolean
              || value instanceof Byte || value instanceof Short
              || value instanceof Integer || value instanceof Long || value instanceof Double
              || value instanceof BigInteger || value instanceof BigDecimal
              || value instanceof JSONFunction || value instanceof JSONString
              || value instanceof String ){
           return true;
        }
        return false;
     }
docs: Verifies if value is a valid JSON value.
  
  @param value the value to verify