code: private String getMemberAsString(JsonObject obj, String memberName, String defaultValue) {
          try {
       	   JsonPrimitive value = obj.getAsJsonPrimitive(memberName);
  
  	        if (value != null) {
  	            return value.getAsString();
  	        }
  	        return defaultValue;
  	        
          } catch (ClassCastException | IllegalStateException e) {
              throw new JsonParseException("Not a JSON string", e);
          }
      }
docs: getMember
  @param obj
  @param memberName
  @param defaultValue
  
  @return