GSON: How to get a case insensitive element from Json?

Code shown below works well when JSON object contains jsonKey as it was passed to the method. I wonder ... if there is a way to get a value assigned to a case insensitive representation of a key?

Example:

public String getOutputEventDescription(JsonElement outputEvent) throws ParserException {
    return retrieveString(outputEvent, DESCRIPTION);
}

Should work regardless whether DESCRIPTION is defined as "Description", "description" or "DeScRipTIOn"

protected String retrieveString(JsonElement e, String jsonKey) throws ParserException {

JsonElement value = e.getAsJsonObject().get(jsonKey);

if (value == null) {
    throw new ParserException("Key not found: " + jsonKey);
}

if (value.getAsString().trim().isEmpty()) {
    throw new ParserException("Key is empty: " + jsonKey);
}

return e.getAsJsonObject().get(jsonKey).getAsString();
}