legacy/src/main/java/thredds/crawlabledataset/s3/S3URI.java
public String getKeyWithTrailingDelimiter() {
        if (key == null) {
            return null;
        } else {
            assert !key.endsWith(S3_DELIMITER) : "Didn't we strip this in the ctor?";
            return key + S3_DELIMITER;
        }
    }
public String getKeyWithTrailingDelimiter() {
        if (key == null) {
            return null;
        } else {
            assert !key.endsWith(S3_DELIMITER) : "Didn't we strip this in the ctor?";
            return key + S3_DELIMITER;
        }
    }
Returns the key, adding a trailing {@link #S3_DELIMITER delimiter}.
Returns {@code null} if the key is {@code null}.

@return  the key, with a trailing delimiter.